What happens to his transaction after? It will simply burn fees and get back to his wallet (automatically?) or or his transaction will stuck someone in blockchain and he will have to spend extra funds to move or accelerate it ?
Someone correct me if I'm wrong, but you get the entire amount sent back to the originating wallet. Makes sense, because the transaction was never included in a block and so the miners shouldn't get any fee.
And yeah, the network seems really congested right now. I assume this is because of the price rise over the last couple of days, which is causing a lot of buying and selling--and this has happened before. There are some transaction accelerators out there, but I don't know how legitimate any of them are.