"How the referee misses the penalty, I do not know," Robson said after the 3-1 defeat at Highbury.
"It is a real lash at Curtis Davies. For me, that has cost us the game."
"It simplifies it for us now by the fact we have got to win our last two home games but the players are capable.
"It was a decent performance from us, but we have got nothing out of it.
"We have got to keep going. If we can take it to the last game of the season again, then that is the way we are going to have to do it."