Had an incident at work (delivery), curious if I handled fall out correctly?

So does of all I will start off by stating this would not even have gotten to this point had I not gotten aggravated.So it was raining, already a super shitty night and I get a delivery to a 3rd floor. I was pounding loudly like asked and the guy comes out super pissed, guess it was a wrong address? I was already standing in the rain for like 5 minutes as is. He's yelling at me, tells me he's gonna beat my ass and such and shuts the door, as I walk away I say something like "fuck that I'll beat your ass" but didn't think he could hear me but did, I'm already half way to the stairs, he's yelling for me to come back and such and I am at the stairs with pillars between us, I stay there because I see him grab his holstered gun and start to draw it, if I went to the half way landing he would have a clean shot, so I stood behind a pillar hand on my gun, I had mine drawn till just a scrap of barrel was left in my waste band. He eventually didn't draw and went inside.First off I know I shouldn't of said what I said, it was just the shittiest day, in the shittiest apartment complex (druggy heaven) in shitty weather.What I am curious about though is was I correct on not fully drawing (he couldn't see I had a gun but if I drew fully he would have) or should I have drawn fully to be 1 step ahead in defense?Should I have just booked it down the stairs or was it better I stayed with multiple barriers in between us? This was my first "true" encounter with someone on the other end having a gun too and it made me think I fucked up positioning and if I didn't take enough precautions once his gun started to come in play. Was it the best choice to not draw and engage then? I mean I'm alive, he's alive... That's the best outcome right? I wasn't afraid of getting shot, I was afraid of having to shoot him... I didn't want too.He was the aggressor from the start and I even tried to disengage from the situation, so while I was stupid I was legal.E: to add, once he reholstered and turned to his door, I reholstered and flew down the stairs calling 911 and got to a public store and hid safely until cops arrived, which the arriving cop then sweeped me 3 times with my own gun trying to figure out where the mag release was :/ via /r/CCW http://ift.tt/2wLGv3F