- Spend 45 minutes crafting a response to a Flow post.
- Enter '[[' and the magic VE window comes up to enter your interwiki phab link.
- Realize it's not what where you want to insert it, press [Esc] to dismiss the VE dialog.
Result the entire ^%$@#*! reply window vanishes, along with all your text. No "Are you sure" prompt. It's gone. It's not even in the Firefox browser sessionstore. Oh fuuuuuuuuuu...
Happens in chromium as well.