I'm a bit gobsmacked and can't see how this could be reasonable (from his point of view). I can't see why any adult would behave like this....
The story is-
Yesterday was a lovely sunny day in the park so me, DD (4yrs1mth) and DS (20 months) went there for the afternoon. Late on, about 5 30 pm I lost DD for a bit while i was changing DS' nappy. Not worried because it is a big busy playground with the play area safely fenced off, i went looking for her. Eventually I found her queieing for a 'big' swing - standing beside a man who was pushing a child. She said 'I can't come I am queueing Mummy'. Fair enough. i was impressed she was standing so nicely and queueing.
There were 2 others around 8 or 10 yrs old queuing on the other side of the 2 swings and both swings were in use. It looked as though all the 4 other kids there belonged with this man. I said 'Come on, 2 minutes more then we have to go' and she said in a panic to the man and his children 'I've only got 2 minutes, can't I pleeeeease have a go?!'.
In his shoes I would have got my child off to give another child a quick go if they had been waiting so nicely and patiently and had to leave shortly. However I would also understand if the man had just said nothing and carried on pushing his child (although secretly might have thought him a bit mean). But oh no! He instead said very loudly so that she was humiliated and I could easily hear across the playground, 'NO! You are in the queue. That little girl is in front of you. It's NOT your turn. The world doesn't revolve around you you know'

Not quite the happy, sharing, sunny vibe of the playpark a moment before!
She burst into noisy sobs. I gathered her up and rushed away telling her to ignore the mean man.
Later I went up to him and said 'My daughter is only just 4 you know. What you did then was unnecessary and humiliating for her and she was very upset'. His response? A shrug and 'Well she's VERY pushy' with his arms crossed. PUSHY? Can this word be applied to a girl who is almost still a toddler and was queuing nicely, albeit a bit desperate for her turn because she is only just 4????
Who's being unreasonable please? She went to bed crying about it, because the man's daughter also told her mean things like 'I don't care about you little girl'. And these were 'nice' middle class types in an expensive area...!!