I can't even begin to list the mistakes you made, but I will mention two.
1. You advanced. You actively went out looking for the BG. Police take a dim view of civilians doing that and you could have been the one in jail if a situation occurred, especially since the BG was incorrectly identified on the phone.
2. You grabbed a PAINTBALL gun??? Are you crazy? MAYBE an inexperienced BG would be scared, but if he identified it as a PB gun, you'd be in some deep kimchee. An experienced BG, if armed, would not have hesitated to use his own weapon, putting you on the defensive instead of the offensive. You NEVER bluff on the street. Someone will call it.
Frankly, it sounds like a bunch of vigilanties calling around, grabbing ball bats and stuff, and getting up a lynch mob to go after the BG. WE ARE NOT LEOS!!! Law enforcement and arrest/detainment are their job, not ours. We don't run around playing "cops and robbers". The ONLY reason we carry guns is for protection of life. You can NOT use that gun unless you are in fear of your life of severe bodily injury. The BG has to have means, intent, and opportunity.
All I can say is I hope you learned several things from this. It could have ended tragically.