I think there is a deeper problem here with HR. Uber didn't care enough to figure out whether it was sexist or not (or even care enough to do anything about it at all). That means Uber is sexist simply by not caring enough to check (regardless of whether this was or wasn't sexism).

* As always a lot of caveats apply: If sexism is defined as legally culpable discrimination of a protected class (rather than looser social definitions, or even broader sociology definitions). If we take her statements at face value.