You need more resources. You didn't have any choices. If your stoker had pepper spray that worked, she wouldn't have worried about getting fed to the wolves. **** whistle works really well with nearly all dogs too.
If you are off the bike and the dog holds still, that's a chance to pet a dog and make a friend. I have a few Labrador friends stashed here and there who love to lick the salt off me.
When you can't predict the future, it is impossible to say if there was a better "right' thing you could have done. As long as the choice you made works out, you have to leave it at that. Every once in a while my stoker and I will decide we have a slow leak and stop to inspect the tires. Invariably (so far) the tires are fine. Having previously had some undesirable experiences with flat tires, we are bothered not at all by being wrong, because we gain peace of mind by inspecting the fully inflated tires.