Yes, that's true. My original point still stands though. That commit will have a PR associated with it. You can go to it and see the details of all commits that were used for the merge commit that went into master. Not really a lot of extra work to go to the PR if you're investigating that deep.

> Even if the original branch is still floating around somewhere, that would still be an extra hassle.

If the branch deletion setting when merging a PR is selected, then only the origin branch will be deleted. If you're the one doing the PR and you don't delete your local branches you'll be able to see it locally. In the other case where is someone else's then it becomes harder, and I agree it's an extra hassle.

In my work I try to mandate PR's to be as small as possible, but not smaller. Big PR's do happen, but that and resorting to git blame or bisect happens maybe 2-3 times a year. I think the general rules for source control followed by the team are more important than the implementation details and git magic.