This is a really poor attempt at analysing the decision.
We won really well with Rodri last week, and as the match thread can attest to, Fernandinho got exactly the same treatement as Rodri in the first half, getting caught a few times and misplacing passes.
Bottled it? Seriously? Get a grip.
It's inevitable when you play a side like PSG going hell for leather in the first half at a pace they can't even sustain through the match that your 6 will get caught on the ball a few times. People need to accept it will happen and stop trying to pretend it's a Rodri issue - Klopp used to specifically target Fernandinho and we conceded goals from him being dispossessed in the past. The only way to stop it is to play over the press instead of through it, but Pep chooses to back our midfield.
They are both fantastic 6's, and Fernandinho likely got the nod because of what happened in the second half when things got nasty and cool heads were needed. Fern calmed everyone down, he whispered in the referee's ear and he wound PSG up until they got a man sent off.
That's stuff Rodri will pick up over the years.