I ran into this a couple times today; a reviewer would LGTM my CL, and then I would upload a small followup patch to fix some test or something, and then it wouldn't be LGTMed anymore. I think this used to work :( It's rather annoying.

https://chromium-review.googlesource.com/c/367487/ is an example (look at about before 5:40)

Also, there's a bunch of spam about setting people to REVIEWER which is both annoying, and I think confuses the commit bot sometimes?