A FRUSTRATED Sam Allardyce has hit out at referee Steve Tanner – insisting his second half howler helped cost Rovers their place in the FA Cup quarter-finals.

The Blackburn Rovers boss knows his side’s lack of killer instinct in front of goal was to blame for not killing off Coventry in a dominant first half, but still feels his side should be in the last eight of the competition.

Minutes after Aron Gunnarsson’s equaliser had cancelled out Roque Santa Cruz’s early opener, Rovers thought they had regained the lead when Gael Givet glanced home David Dunn’s free-kick.

Mr Tanner ruled Givet had tugged Gunnarsson’s shirt to beat him to the ball though and Coventry took full advantage of the let-off as Michael Doyle fired them ahead just seven minutes later.

Chris Samba spared the hosts blushes in the dying seconds, to secure a 2-2 draw, but Allardyce insists it would have been a different story had Givet’s header been allowed to stand.

He said: “We found ourselves back to 1-1 which was not too much of a problem as long as we got our game back together, and we made an instant response with a very good goal from a freekick which, bafflingly for me and everybody else in our camp, has been disallowed. That would have been 2-1 and probably seen us through.

“According to the fourth official, the referee claims there was a pulling of the shirt but I’ve looked at it several times on the replay from two or three different angles and there is nothing wrong with the goal whatsoever.

“We haven’t had to swallow that one and it’s cost us a defeat, but it is a poor decision unfortunately. It meant they go down the other end and get a deflection, and what should perhaps have been a comfortable victory for us has been a scrappy 2-2 draw.

“I try to steer clear of the controversy that may surround decisions. Yes, people will make mistakes but you can’t make major errors, and for me that today was a major error.”

After Santa Cruz had drilled Rovers into the perfect start, the Ewood Park faithful saw a host of chances wasted as Coventry were handed an FA Cup lifeline.

David Dunn, Carlos Villanueva and Jason Roberts all missed good chances to effectively kill the game off – something that Allardyce admits is becoming an increasingly concerning theme.

“It was a relief in the end but after the first half I was disappointed in the way we went about our task in the second half,” he said.

“You’ve got to give Coventry credit for taking the chances to push on and take more and more risks that we didn’t cope with very well.

“But, for me, in the first half when you’re in control of the game you have to make sure you see the opposition off if you get the opportunity.

“The quality of the goal we scored then went missing with chances that were easier to convert than the one Roque converted.

“We’ll probably go and play on a Tuesday and it’s a very difficult tie now.

"More a case of seeing what we’ve got available when that comes around and go there and do the job we should have done here.”