Sounds very scary and I completely understand where you're coming from - we had a similar thing with a Rottie last summer which terrorised our two, it wasn't actually trying to bite them or anything but just throwing its weight around and following them - basically being a bully and freaking them out to the point they were both screaming and running away from it (but unfortunately in this case the owner wasn't at all responsible and completely ignored my pleas for her to call her dog away so that we could get on our way
).
I do think in this case at least the owner tried to sort it out as quickly as possible. I think the fact that the greyhound was jumping up at you is just because you'd picked your dog up - we had a similar thing with a couple of staffies who had it in for Bella and Ali picked her up (owners were busy smoking fags the other side of the park and taking no notice at all even with us shouting at them). As soon as Bella was in Ali's arms the dogs then started leaping up and down trying to bite her on the bum and Ali got a few nips in the process (but I don't think they were people-aggressive dogs, it was more like co-lateral damage).
Greyhounds can be boisterous, there used to be one near us who always used to charge at Bella and then some to a screeching halt in front of her, and initially she was really freaked but then got used to it and would just tell it off.
Do take the advice of trying not to let your dogs pick up on the fact that you're now nervous of greyhounds, it can really make things worse (we had this with staffies - Bella was attacked 3 or 4 times and I ended up so that if I saw one my heart would be leaping out of my chest and Bella definitely picked up on that. When I started to calm down about them, so did she
). It's really hard but just try and be positive and find some more placid greyhounds for them to meet if possible.
