I don't agree with the threats in any way, that's just bullshit that should never happen but if someone is having a pop at him at kick-off then he's got every right to tell them to fuck right off. If he's not sat down for 5-10 minutes and it's persistent fair enough but it's kick-off and you expect a bit of excitement and release of tension. You don't know his circumstances, he may have had something shitty happen recently and it's a chance to let go a bit, he'd have probably calmed down after the original outburst if do gooders weren't telling him what to do. Personally I'd be having a go right back if anyone told me to sit down that early into a game.
If he's leaving his kid that's a different matter, that makes him an absolute çunt.