No assist for Sion

I posted this a few months ago and still think this is a bug that needs to be fixed. Scenario: ARAM and I'm talking to everyone on my team. is on the enemy team. My buddy was playing and I was playing . Note that this is before the rework but the concept of this still holds true since time bombs can still stick to minions. He convinced me that we could get a <5% health for first blood if I put a time bomb on a minion and he bash it onto the . We go for it and the minion bash did not hit but made it so that my time bomb was in range to kill for first blood. We checked immediately and saw that did not get the assist. The only way we got the kill was his minion bash put my time bomb into range for the kill. I posted this and reported it and a boards overviewer replied and told me that since did not do any direct damage to this is why no assist was rewarded. The thing is it was a organized play. We talked strategically about it and my first blood was 100% impossible had it not been for minion bash. It is not my job to figure out dynamics of a kill, gameplay or anything but one thing is for sure. I used mana for that time bomb and Sion used mana for that minion bash.