I would usually agree in principle, as it is a thing, but to be honest the information is all right there in her OP that something isn't 'right' in their relationship.
He doesn't just raise his voice to her son, he tells him he's got no manners, that he doesn't want to eat dinner with him again (carrying it on in to the future), and then tells him to go to bed (obviously skipping the film they had planned anyway), when the son starts crying he turns on OP saying she isn't raising him correctly, and that he is a rude child for ignoring him earlier in the day, all in front of her son.
It is WAY over the top by anyone's standards, and yes, abusive IMO, a few simple stern words would have sufficed if he really didn't think he was listening to OP enough for his liking, not the tirade of abuse that he metered out to both of them, he didn't want to discipline him at all, he wanted to vent his anger at both of them.
OP then went to bed with her son to get away from the situation instead of confront it, she finishes by saying she doesn't want to stay and she knows her dad will never apologise for his actions.
It's all right there in the OP that he is emotional abusive, and she may be afraid of him, if you've never had an emotional abusive parent, then whoopedy fucking doo for you, it doesn't mean OP is fabricating anything.. as soon as I read her OP I knew exactly what sort of 'man' he is.