It is hard to watch, but do keep an eye on the situation. Especially if you see the beagle out and about on her own, attach a leash and teach her no going in the street, and what manners you can when the mean owner's not looking ...

I do like the idea of asking if Kalou could go for walks with you and your dog, even if you use the "it will help with my dog's socialization" as an excuse ...