I've seen someone do it. If your workflow is 'git push -f feature' after rebasing, instead of 'git push feature -f', you can tap enter and break the world.
Edit did you mean to say (plus)feature or is something ruining the formatting? That seems to be how to specify only one branch. Yuck.
I'm lucky I haven't run into this, I guess, because I set my push default to simple a long time ago, so long ago I can't even remember why.
git push -f (enter) => Death to all branches. git push feature -f => Can only ever force push the feature branch
No matter when you press enter in the second line, intentionally or accidentally, you can't break all branches.