Oh, sorry. It's hard to tell, it doesn't look like you made contact with him in the mirror, i.e there is no shown visual contact, but the way his car moved onto the grass kind of looks like there was contact. If there were any contact there that pushed him onto the grass on a straight, I think in the FIA F1 regulations, if you force a car onto the grass on a straight by making contact, it is seen as an illegal overtake, as it could put the driver in danger, in real life.
Also bare in mind, in some lobbies, the connection isn't the best, so the cars may be in different positions on the players screen. It has happened with my friend and myself before. When we both sent each others footage to each other, we saw two different incidents,one when he, on my screen cut my up and consequently I went into the barrier, and on the other just, I suddenly lost my front wing and spun off into the barrier on a straight