Unfortunate, as this we my first chess.com game, I've been playing for months on playchess.com with players all over the world, never had it happen before.
opponent abandons game
For this reason I never play Live games that are more than 10 minutes. If I want a longer game, I play turn-based.
People can be bad sports. Surprise surprise. They figure they can't beat you on the game, they'll win with psychology. Just shrug it off and remember: "My skills made them flee in despair" :)

My very first Live game, won position; Rook, Bishop, Pawn and King vs. King, my opponent simply walked away without clicking the Resign button. So now I'm stuck here waiting for the game clock to wind down on his move.
I don't believe it was a disconnect, as we'd been playing just fine for over an hour.