CL in question: https://chromium-review.googlesource.com/#/c/439891/ and friends.

Note that this was dependent on a few other CLs that had already been verified by the pre-cq.

pre-cq-launcher that took actions on this CL: https://uberchromegw.corp.google.com/i/chromeos/builders/pre-cq-launcher/builds/8641

Symptom:
CL kicked out with messages about conflict with ToT. The posted link to pre-cq slaves are invalid links:
Patch Set 5:
A trybot failed to apply your change in https://luci-milo.appspot.com/buildbot/chromiumos.tryserver/whirlwind-no-vmtest-pre-cq/5439 . CL:439891 conflicted with ToT.
The conflicting files are amongst:
server/afe_utils.py
server/afe_utils_unittest.py

Looking at the buildbucket request for whirlwind pre-cq that was actually created for the CL: http://shortn/_EmIOQssGNe, we find that the build succeeded: https://uberchromegw.corp.google.com/i/chromiumos.tryserver/builders/no_vmtest_pre_cq/builds/5439


In fact, the pre-cq-launcher later claims that this CL has already been verified.
Meanwhile, the CL was kicked out.

What gives?