diff --git a/suite/apps/tableaux/components/canvas/RoomCanvas.test.tsx b/suite/apps/tableaux/components/canvas/RoomCanvas.test.tsx
new file mode 100644
index 00000000..2f02914e
--- /dev/null
+++ b/suite/apps/tableaux/components/canvas/RoomCanvas.test.tsx
@@ -0,0 +1,64 @@
+import { describe, it, expect, beforeEach } from 'vitest'
+import { render, fireEvent, act } from '@testing-library/react'
+import RoomCanvas from './RoomCanvas'
+import { useStore } from '../../store/useStore'
+import { openPlan } from '../../test/openPlan'
+
+const pointer = (type: string, x: number, y: number) =>
+  act(() => {
+    window.dispatchEvent(new MouseEvent(type, { clientX: x, clientY: y }))
+  })
+
+// A cancelled pointer (a system gesture, an interrupted touch) is not a
+// release: the draft must go, and nothing it would have committed may happen.
+describe('RoomCanvas drawing, when the pointer is cancelled', () => {
+  beforeEach(() => {
+    openPlan({})
+  })
+
+  it('drops a half-drawn zone and adds nothing', () => {
+    useStore.setState({ activeTool: 'zone' })
+    const { container } = render(<RoomCanvas />)
+    const canvas = container.querySelector('[data-tour="seating.canvas"]')!
+
+    fireEvent.pointerDown(canvas, { button: 0, clientX: 10, clientY: 10 })
+    pointer('pointermove', 200, 200)
+    expect(container.querySelector('[class*="draftZone"]')).not.toBeNull()
+
+    pointer('pointercancel', 200, 200)
+    expect(container.querySelector('[class*="draftZone"]')).toBeNull()
+
+    // A release after the cancel belongs to no drag.
+    pointer('pointerup', 200, 200)
+    expect(Object.keys(useStore.getState().zones)).toHaveLength(0)
+    expect(useStore.getState().activeTool).toBe('select')
+  })
+
+  it('drops a half-drawn calibration line and opens no dialog', () => {
+    useStore.setState({ activeTool: 'calibrate' })
+    const { container } = render(<RoomCanvas />)
+    const canvas = container.querySelector('[data-tour="seating.canvas"]')!
+
+    fireEvent.pointerDown(canvas, { button: 0, clientX: 10, clientY: 10 })
+    pointer('pointermove', 200, 200)
+    expect(container.querySelector('line[stroke-dasharray]')).not.toBeNull()
+
+    pointer('pointercancel', 200, 200)
+    expect(container.querySelector('line[stroke-dasharray]')).toBeNull()
+
+    pointer('pointerup', 200, 200)
+    expect(useStore.getState().modal).toBeNull()
+    expect(useStore.getState().activeTool).toBe('select')
+  })
+
+  it('still adds a zone on an ordinary release', () => {
+    useStore.setState({ activeTool: 'zone' })
+    const { container } = render(<RoomCanvas />)
+    const canvas = container.querySelector('[data-tour="seating.canvas"]')!
+
+    fireEvent.pointerDown(canvas, { button: 0, clientX: 10, clientY: 10 })
+    pointer('pointermove', 200, 200)
+    pointer('pointerup', 200, 200)
+    expect(Object.keys(useStore.getState().zones)).toHaveLength(1)
+  })
+})
diff --git a/suite/apps/tableaux/components/canvas/RoomCanvas.tsx b/suite/apps/tableaux/components/canvas/RoomCanvas.tsx
index 8cf5317e..c88437cc 100644
--- a/suite/apps/tableaux/components/canvas/RoomCanvas.tsx
+++ b/suite/apps/tableaux/components/canvas/RoomCanvas.tsx
@@ -141,11 +141,9 @@ export default function RoomCanvas() {
     [canvas.panX, canvas.panY, canvas.zoom]
   )
 
-  // TODO(ux-audit): startZoneDraw and startCalibrate below both register only
-  // pointermove/pointerup on window, no pointercancel (same bug class fixed
-  // in TableHandles.jsx, see tmp/ux-audit.md #C13) — a pointer release/
-  // cancel outside the window can strand a draft zone or calibration line
-  // mid-draw. See tmp/ux-audit.md #C14.
+  // A cancelled pointer (a system gesture, an interrupted touch) is not a
+  // release: it drops the draft and commits nothing. Without listening for it
+  // the draft stayed on the canvas, still following the pointer.
   const startZoneDraw = (e: ReactPointerEvent) => {
     const start = screenToCanvas(e.clientX, e.clientY)
     const onMove = (ev: PointerEvent) => {
@@ -153,9 +151,15 @@ export default function RoomCanvas() {
       draftRef.current = rect
       setDraftZone(rect)
     }
-    const onUp = () => {
+    const stop = () => {
       window.removeEventListener('pointermove', onMove)
       window.removeEventListener('pointerup', onUp)
+      window.removeEventListener('pointercancel', stop)
+      draftRef.current = null
+      setDraftZone(null)
+      setActiveTool('select')
+    }
+    const onUp = () => {
       const r = draftRef.current
       if (r && r.width > 16 && r.height > 16) {
         addZone({
@@ -167,12 +171,11 @@ export default function RoomCanvas() {
           shape: 'rect',
         })
       }
-      draftRef.current = null
-      setDraftZone(null)
-      setActiveTool('select')
+      stop()
     }
     window.addEventListener('pointermove', onMove)
     window.addEventListener('pointerup', onUp)
+    window.addEventListener('pointercancel', stop)
   }
 
   const startCalibrate = (e: ReactPointerEvent) => {
@@ -183,11 +186,15 @@ export default function RoomCanvas() {
       line = { x1: start.x, y1: start.y, x2: end.x, y2: end.y }
       setDraftLine(line)
     }
-    const onUp = () => {
+    const stop = () => {
       window.removeEventListener('pointermove', onMove)
       window.removeEventListener('pointerup', onUp)
+      window.removeEventListener('pointercancel', stop)
       setDraftLine(null)
       setActiveTool('select')
+    }
+    const onUp = () => {
+      stop()
       if (line) {
         const dist = Math.hypot(line.x2 - line.x1, line.y2 - line.y1)
         if (dist > 8) openModal('calibrate', { pixelDistance: dist })
@@ -195,6 +202,7 @@ export default function RoomCanvas() {
     }
     window.addEventListener('pointermove', onMove)
     window.addEventListener('pointerup', onUp)
+    window.addEventListener('pointercancel', stop)
   }
 
   // ── polygon room drawing: click to drop vertices, Enter/click-start to close ──
diff --git a/suite/apps/tableaux/hooks/useCanvasPanZoom.ts b/suite/apps/tableaux/hooks/useCanvasPanZoom.ts
index f4186b35..0c37e188 100644
--- a/suite/apps/tableaux/hooks/useCanvasPanZoom.ts
+++ b/suite/apps/tableaux/hooks/useCanvasPanZoom.ts
@@ -65,11 +65,6 @@ export function useCanvasPanZoom() {
       }
       window.addEventListener('pointermove', onMove)
       window.addEventListener('pointerup', onUp)
-      // TODO(ux-audit): no pointercancel listener (same bug class fixed in
-      // TableHandles.jsx — see tmp/ux-audit.md #C13). A pointer release/
-      // cancel outside the window here leaves isPanning stuck true (cursor
-      // stuck "grabbing"). RoomCanvas.jsx's zone-draw/calibration-line
-      // dragging has the same gap. See tmp/ux-audit.md #C14.
       window.addEventListener('pointercancel', onUp)
     },
     [setCanvas]