Premature Resignation

In this game my opponent made one crucial error in leaving his rook exposed to my queens attack leaving his entire back row available to my plundering. I am not the greatest player in the world in fact alot of the time my play is deplorable. I want to learn the inner workings of the game...was this the proper time for him to resign, is this what a grand master would do if for whatever reason he made the same mistake would he offer you his hand and say well played or should he have played out a bit longer hoping I would blunder...is this a premature resignation or just knowing your beat.
Game 3113707

my opinion is if for whatever reason a grandmaster made the mistake as in move 13 and I did the same move as I did in this game he would resign at that point knowing his backrow was dominated and there is nothing that can be done...what are your thoughts

being a rook and a minor piece down is kind of hopeless. of course most 1100s would keep playing...

Which is why they are 1100