A 600 elo beat me with a 86 precision, is it legit

This 586 elo guy just destroyed me and the chess.com analysis says they have played with a 86.0. Do you thing it was legit?

It looked legit, a high accuracy is common when you beat someone in the opening

It is legit, you blundered in the opening and your oponent capitalized on your mistakes, which tends to lead to higher accuracies for your opponents in contrast to when you get to, per say an equal middle game with no clear plans for either side, which tends to lead to more inaccuracies and mistakes, happens

They are a friend of mine, since I had higher rating he played with a full set while I had king, pawns, one bishop and one horse

When you start out by giving odds of pieces, you should expect to lose. The side with the extra material will likely be more cautious to capitalize on the advantage.

That's completely legit. When you start using openings you'll often see accuracy in the 90's and then someone will accuse you of being "suspicious"