As to the OP, it sounds to me like the photographer was having a stressful day and made the error of letting it show. Hopefully, it didn't show in her photos.
Personally, I would have moved, then whinged to other people about it, just like the OP seems to be doing. But if I were camping and with my dog, I would have been chilled out, and probably offered to help if they needed it.
Why make a scene which would only serve to punish the innocent couple and ruin what should be a good day for them? Ten minutes isn't going to kill you, and didn't ruin your day. What ruined your day is your response to it (anyone remember Ken Keyes????). You don't have to view every inconvenience as a personal challenge or battle, and you don't have to try and 'win' every one of them.
You saved the couple's shoot and should feel good about THAT, not still annoyed because the photographer wasn't nice enough.
my 2 cents.