Agree that was likely the motivation.

His comment was still an example of misogynoir though. To me it tracks more sexist, but Black people have been compared to animals as a means to dehumanize them. Bitch is used in the same fashion to dehumanize women more specifically. So the use of dog hits both of those but it hits closer to the misogynistic use of 'bitch'.

Further, regardless of his motivation, racism and sexism come out in these emotional moments of aggrievement. So on the end, is the motivation more important than the response that lays bare someone's character?