YANBU to not want this kid round again but YABU if this friend is as close as you say you are, and you let them get away with it.
You should be able to say "Sorry, that is just not going to be possible. Little Johnny really upset DD today - the snatching, the hurting her, the breaking of her toys - so I don't think they are a good fit for playdates, especially since you ignored both his behaviour, and me, in favour of your phone for the entire playdate."
Why would you let your DD be so disrespected and hurt so badly by another child, in her own home and say nothing? I get not wanting to parent other people's children, especially when they're right there, but you could have nipped this in the bud. Even if your friend didn't see what was happening you could have dealt with the immediate issue of her DS' behaviour and then asked her to keep a better eye on him.
"Johnny, do not hurt DD. Stop that now. Friend, can you please speak with your son, I've just seen him force my daughter's hand open to forcibly take her toy from her and he's really hurt her"
If she doesn't respond or do anything beyond shout no at her son, that's the point where you say "OK, this isn't working, neither of you are respecting me, my DD or my home so it's time for you two to leave."