When I read this it set off all kinds of alarm bells in my mind but I didn't want to post an unconsidered response. So here is my considered one.
We all know that Bruce and Rod (possibly for different reasons) take a special interest in the victims of cancer. And Bruce has visited kids in cancer care facilities in the past. But there are a lot of kids with cancer, unfortunately, and this one kid has been granted preferential treatment for some reason (may have been a particularly deserving case? Or possibly Mum just knew how to get in touch with Rod? I don't know). Bruce probably thought it would do no harm, and was a nice gesture.
But the thing is, after said meeting takes place and the kid (or, more likely, his doting mother) splashes the pictures all over Facebook, Instagram et al someone else is going to come along and say "my kid has cancer too - does he/she also get a one-to-one meeting with Bruce?" Eventually they'll have to start saying no, from purely practical considerations. And at that point someone is going to get really hurt. Maybe Paddy foresaw this and thought it was better not to set a potentially dangerous precedent.
Meanwhile the kid's mother gets pissy because someone doesn't share her view that her kid is inherently more important than everyone else's kids (which seems to be fairly common) and vents her frustrations on Facebook where she gets to demonise Paddy and Bruce still gets to be the hero. But however you look at it, the account as given here is biased, one-sided and uncorroborated. I think that to take it at face value would be at the very least unwise.