"I've seen a replay and he (Chopra) was onside, and we thought that at the time.
"We could tell by the player's reaction and having seen it again, it is disappointing.
"But we had other opportunities to score."
When asked whether he had spoken to referee Mike Riley, Keane replied: "Is there a point? Is he going to change his mind? "
When it was suggested the ruled-out goal was indicative of the bad luck his team is having this season, Keane responded: "I'm not going to go down the road of luck.
"When officials make decisions it's not about luck, it's about getting their calls right.
"But we are not here to blame the officials for our away form, and it's nothing to do with luck because I believe you make your luck in these games.
"We had other chances and if you don't take those then you've no-one else to blame but yourself.
"At the end of the day this is definitely two points dropped."