Mangroves are not all testy, I have a sub-adult female (about 4-5 ft. long) who is relatively calm, though a little flighty...a bite from one is probably not a medical emergency, but is still something you want to do your best to avoid. Although western hogs are considered "venomous" the venom is so weak i don't think anyone has suffered any symptoms of envenomation from them...in other words, it doesn't have any known effect on humans. What's even more suprising is the fact you were even bitten by one, because they hardly ever strike with the intention of biting you. Mangroves are a bit different, and from what i've heard (never been bitten personally), it can be a painful affair, though nothing compared to a viper or elapid bite, in terms of symptoms or the need for medical attention. But like i said, you still probably want to do your best to avoid being tagged regardless of the outcome...
AP