Robinni, I'm sorry if you think my post was harsh but the OP's whole premise was about children running around in a pub where food/drinks are served. I suppose that broadly you're in agreement because, if children were running around your son wouldn't have cause to react.
I've had numerous experiences of dodging children running around with parents blithely unaware or just not caring, it's really annoying. I wouldn't comment on parents of children with SEN because firstly I'm not one myself and secondly, I've never, ever seen a child with obvious SEN (or their parent) being tutted at, or eyebrows raised or anything like that. If that happens then that's very sad and yes, people should be more tolerant.
That said, no child, with SEN or not, should be running around and that's really all there is to it. It's not about the child, really, it's about the staff trying to do their job - and consideration for the other customers. It's not that difficult and PP nailed it by stating that child-friendly doesn't mean it is for children.
Parents/guardians/whatever - are responsible for the child(ren) in their care and it's not the job of other people to make allowances for them if/when they encroach on other people's space or put others are risk. That was my take away from the thread.