You should replay that particular play.

RGE had baron buff and a 9k gold lead. They stay together to destroy the turret but then like morons ( happens in solo all the time) they left poor adc to kill the inhibitor alone with just renekton in the vicinity ( he did not even dmg the inhib). They could have waited for a new baron buffed wave but nooooo...

So cait runs back but gets flanked with nice knock up from hidden aatrox which leads to burning all ults, flash, galeforce, TK ult etc so she stays alive. She at least ults on lissandra forcing caps to use her ult. If caps had his ulti it was over. Because he would use it on jarvan, either kill him or bb would use TP on the cannon minion to destroy turret n2 and it would be game.

I mean this has nothing to do with cait. Every other adc would suffer the same when their team leaves them alone to kill the inhib because they want to reset 2 seconds earlier. Bad comm.