I disagree in this case. The guy didn't do anything wrong. Didn't assault anybody, didn't say anything controversial. Was just, like you said, being a dick. And I could see the situation playing out, his wife and old MIL in the wheelchair, open the door and are all like "oh my heavens you young whippersnappers" and he springs into hero mode.
The dad did, however, venture into legal gray area (entering a women's bathroom). AND.....something happened before the video that prompted him to start recording. Perhaps he then started being slow and taking his time.
Like I said, it's all freaking dumb. No idea why this went viral. Who the heck even cares.