High elo players: What is the right decision in this moment?

Let's say I'm duoing with a friend botlane as a support and we get a kill/shove lane. As I ward bush (we're on red side) I notice veigar is being two-manned mid and our warwick jg is nearby top river, so I head through bot river and tell my friend over curse that I'm going to help veigar and for him to play safe (blitz + ezreal bot). I make it to mid, peeling off a lissandra from helping kindred while our warwick/gangplank kills kindred. We notice Olaf trying to run past our mid tower to escape so we go after him too.

Meanwhile my duo gets hooked and uses flash/heal to escape. As we're killing Olaf my duo walks towards creep for more farm and gets hooked again. He thinks I should (or any support should) only feed their adc and not have to worry about other lanes (his argument is that they were already doing well). My argument is that we had a good yet toxic player who I felt would throw if tilted, therefore I decided it would be in our best interest to play safe, roam, ensure gank kills and then group push wherever our teammates go. He strongly disagrees as he says I didn't really help them out mid and I could've double killed bot with him.