Etiquette of tapping out to save time on MTGO

So tonight I was playing a 4p game on MTGO. It was 3 janky decks against a pretty mean Nekusar. I was playing pirate tribal with [[Skeleton Ship]] as my general, so I was jankiest of all and expected to die early. We played until turn 13, all targeting the Nekusar player until he died. One of the players managed to destroy some of the stax pieces with Woodfall Primus, so as soon as the Nekusar player was gone, I noticed the player who had played Primus was tapped out, so I used [[Carrionette]]'s ability from my graveyard to exile Woodfall Primus, since I knew it would come back to bite me.

The person who played it said I was rude and that they had tapped out to save time. Again, this was turn 13. I would never Carrionette a creature if the player had mana up to counter it, and all I had noticed was that they were tapped out.

Was I in the wrong to do this? It seems to me tapping out like that to save time on the first few turns makes sense, but not late game, especially with graveyard shenanigans going on. Again, I didn't notice the player tapping out to save time and take advantage of the situation. I just noticed the lands were tapped and acted accordingly.