Classifying something as a textbook whataboutism is typically itself a rhetorical fallacy. It is rare for it to be used in the sense of identifying a real problem. Normally when it gets invoked someone has an argument, often a reasonable one, and someone else wants to pretend it isn't a valid but can't come up with a logical inconsistency.

In this case nxm's comment has formal problems - it is just irrelevant. True or not, it doesn't justify mowing down cyclists.