I know I'm rather late here but FWIW I agree with the vast majority of posters here who are aghast at this man coming into Poppies' home.
If, when it'd happened, he was immediately full of remorse, if there's never been anything remotely similar before or since and if, off his own back, he had suggested seeking anger management, then maybe the whole "family" getting together thing could have been salvaged.
But he wasn't, there was and he didn't.
Now everyone is supposed to pretend it hasn't happened.
The possibility of it happening again in a house of watchful adults may be remote, but why should that mean he is actually welcomed and included ? What's more, it is equally true that he might get "wound-up" all over again with disastrous consequences.
Think about a full house, full of noise and people, with several children ....... shrieking, bickering, crying, running about, shouting, making lots of noise, messing about with their food etc. Most people - to a degree - would get "wound up" in such a scenario ...... I know I would (being the sort of person who usually prefers peace and quiet) though obviously I don't take to throttling, or throwing kids across the room.
I'd have said the chances of him being "wound up" again are pretty high. Maybe he won't physically assault a child but perhaps he will be verbally unpleasant instead ?
And again, what if your son's memory is prompted by his appearance ?
Sorry ..... but in the total absence of any sort of apology or acceptance of responsibility, someone like this would NEVER come in my house again. If that meant the rest of my family took against me then so be it - their ignorant attitude would matter very little in comparism to my child.