Yes, i agree,

I spoke to the guy afterward and he said that he was so confused with the game after the 3.Nf3 that he felt very uncomfortable.  He made a mistake! Castling would have been a good option.  I would most probably f4 as the queens are off and I do not have to worry that much about castling myself.

Nico, I don't understand why Capt. moved his knight off d7. unless if he didn't see the mate or was he hoping that you won't see it? I'm trying to figure out the continuation of this game if he didn't remove the knight. From my analysis, he could've castled after you captured the pawn at e4. I could be wrong here. Let me know what you think about this.

I'm fairly new to chess.com so please, don't be too hard on me when you respond to this query.