Happened to me once or twice(Making random moves on the board because there's only seconds left on the clock and "accidentally" stumble into a checkmate.
Pretty nice...though why 3...d6 followed by 6...d5? Wasted a tempo there.
I'm also confused with your "not wanting to mess with the pawn structure on your un-castleable queenside while pushing the kingside pawns. Seems fairly dangerous.
I do that all the time. More emberassing than that... resign AFTER you've been mated because you didnt recognize the mate.
Always check... it may be mate
nice one!!
***WARNING SPOILER BELOW***
I moved my queen one square left, but moving it down one and left one works as well.
Well, I don't know how many of you in the timed games have made a checkmate move without realizing it.
I was in a game trying to avoid capture, and stumble into a winning move. Not proud, but I'll take it!