I'd be giving my 3 yr old a stern talking never-ending 12 thats awful and Im shocked at the parents!!!
the same time, he still wants to come over to our house (he just shows up in our garden sometimes)
No way would that continue.
I'd either preempt this or If he turns up i'd explain its not convenient for him to play today and escort him home.
I'd then speak to the parents and say something like
Hi dave/sue,
Can i have a word? In you go tommy i need a private word with your mum/dad.
sue / dave, you know tommy threw stones at me and my children while we were in our garden. I dont understand how you and tommy think things can continue as they did before....His behaviour wasn’t an accident or careless—it was deliberately and extremely dangerous.
What’s really concerning is that he showed no real remorse, and neither did you. You actually seemed unfazed despite the seriousness. I was shocked that something so serious as this didn’t seem to register as unacceptable to you.
Because of that, we don't feel comfortable having him over anymore hei want to be clear he’s not welcome in our garden or around our children.
His behaviour crossed a line, one of us could have spent the day in hospital because of it. We have to put our safety and wellbeing first.
I hope you can understand this is not about being dramatic, but about having a safe and respectful environment for my children.
Any lame apology after this and I'd thank them but say it's too little too late and your position wont change but you sincerely hope hes learned from this and its a life lesson for him.