Welcome to my world

.
I have spent years teaching Fred recall and it remains his weakest behaviour. Some of it is as a result of his start in life and some is him being naughty.
Even when he has stuck the spaniel fingers up at me and gone off for ages I will always 'praise' him when he comes back. Believe me, it is perfectly possible to curse your dog all names under the sun in a singsong happy voice

.
Seriously, even 5 yrs down the line any good recalls are rewarded everytime and the less good or frankly naughty ones are acknowledged but not with food, what I do though is have him close and almost immediately do something I can reward highly - some basic sits or similar.
To be honest though, I wouldn't have tried to recall Dusty in the scenario you write about, I would have kept quiet and just kept moving closer and waited till he was actually disengaging from the pup and then calling him once he was committed to coming to you anyway. He is still very young and play with other dogs will excite him and make him deaf to you. With Chase, my 18 month old trial even now I only give him a command when I know I have an ability to reinforce it if he ignores me, this method is slow going but as my git is the first one I have trained this way he actually is more advanced in obedience than any of my other dogs.