Maybe drop into your local Police Station when you have time - with photographs and of the rubbish before you think about moving it. Just tell them what happened, tell them how shocked you are, the poor state of your hedge and his aggression - maybe they will be minded to go and have a word with him. It is certainly extraordinary behaviour and, of course, he has taken it upon himself to interfere with your property without consulting you or seeking your permission.
The hedging was probably overhanging the pavement? The pavement would be Council property; so they could be asked by anyone in your cul de sac to insist that you cut back your hedge if it constituted a nuisance. Or someone could call on you, in a normal way, and ask whether you could cut the hedge back a bit. No one has the right to cut it themselves or damage or change your hedge boundaries or any of your property without your knowledge or permission. That's ridiculous. That would still be a bad idea even if the hedge was between your own and a neighbour's garden. Not sure whether he is renting or has bought his home but he needs to have someone in authority (especially if he is aggressive and in the wrong) enlighten him about the law and remind him that if he does something like that again, action will be taken against him. If you speak to the Police,they will at least have a record of your complaint just in case he should take it upon himself to do something else in your locale. I wouldn't just let it go - it will encourage him into thinking that his behaviour was o.k. ( I wonder if does need to do something about his extra wide children. )