The most important information you provided was the fact that he's bi-polar. You can't really take in the whole scenario and interpret it just like any other one. Dating someone who's bi-polar is more than a handful. (
Bipolar I ). It sounds like when his phone was off the hook, he was probably in his manic state. Do you know if he takes meds for it? If you can somehow pull it off without agitating him further, try to find out if he's still taking them or if he stopped. If he stopped taking them, that's probably what triggered the mania. Pot could also trigger it.. it depends on the person, though, I think. Alcohol is worse, iirc.
It sounds like, minus the mania, he is really a nice guy. You have to ask yourself if you can deal with his mood episodes.
One of my friends dated a guy who was bi-polar for about 1.5 years. Personally, I think this guy was using his mood disorder as a means to manipulate her. Well, he was manipulating her, but the question was if it was intentional or not. He wasn't a good guy if you looked past the disorder. Your guy doesn't sound like he's truly bad once you strip away the chemical imbalance. Again, it's a handful but if you're willing to deal with it then it's up to you to decide if you want to stay or not.