Proper Conduct

I did something that got some guy really pissed off at me in a match, I feel like I was justified, but I want to be sure.

I played a normal match on summoners rift, won bot lane (the adc and myself did very well, coming out ahead in cs and kills, despite being camped constantly by their jungler). Our jungler did average. Our mid laner did poorly, couldn't handle his lane, but we still were ahead, aside from top. I don't use the term feeder lightly, but top fed, so much so it seemed to be intentional, and he wouldn't listen to advice from any of us. 22 minutes in, a surrender vote comes out, but we're still holding our own, so it only gets 1 vote (the jungler then rage quits). We try to hold our own for like another 5 minutes, in case he dc'd, but he doesn't come back, and we're getting our asses handed to us (their fed champ is at level 18 by the end of the match, and none of us broke 15, it devolved into a slaughter). I send out the surrender vote, the one other person who is doing well agrees with me, and the other two vote no. By the next surrender vote, i talk with my team prior to starting it. I say there's no point to this, adc agrees with me, and the other two still vote no (its been a 36 minute slaughter by this point.

I say in all chart, please end this, I'm done, and go to wait in the item shop, adc joins me. Mid gets pissed off and starts ranting that I'm getting reported, i tell him to do what he wants, but be sure to report the feeder (my feedback is gererally very positive, so this doesn't worry me much). We had two players, one who fed, another who played like crap, and both were refusing to let us end (and we played very well). I felt justified in calling it quits since these two were being unreasonable.

Given the context, was it okay for me to wait in item shop, or is that taboo, something never to be done?