When transforming video sequencer handles, there are limits beyond which you cannot move them which is enforced by the transform code.
The Slip operator ignores these constraints - allowing the strip content to be dragged with offsets that are outside the strip start/end.
- Start a new Video Sequencer Template
- Add a new scene
- Add that scene as a sequence strip.
- Make sure the current frame is in around the middle of the sequence strip.
- Drag the "Strip Offset Start" to 500 (notice the strip shows as flipped).
- Delete the strip.
- Blender Crashes
Attached asan crash output: