A few days ago, I landed two commits that were referenced in  issue 725996 :
* https://bugs.chromium.org/p/chromium/issues/detail?id=725996#c7
* https://bugs.chromium.org/p/chromium/issues/detail?id=725996#c8

which were correctly referenced by bugdroid when they were landed.

They were subsequently reverted, but only one of the commits produced a comment in the bug:
* https://bugs.chromium.org/p/chromium/issues/detail?id=725996#c10

In other words, https://chromium-review.googlesource.com/c/521702/ was committed but did not generated any comment there. I'm not sure if it's because multiple bugs were listed in a single line ("Bug:  725996 ,728584", with no space between the bug numbers) or the fact that issue 728584 is not public.