"Yet for us to get back into a leading position at half time meant we should have had enough to go on and see the game off. To be fair, we had the opportunities early in the second half to do that and at 3-1 I think it would have been a long way back for them after their midweek disappointment.
"But Burnley always had something to chase. They did that in the last ten minutes. They pushed their full backs on and went man for man. They got a goal and good luck to them. The bottom line is goals change games and, if you score the third goal, I don't think there is any way back for them."
Mowbray, who took his side to the semi-finals last year, continued: "We did it the hard way last year when we went all the way to the semi-finals with away draws in every round. We've got to do it again and we'll wait and see. We did the same in the last round and it was practically déjà vu with Burnley's equalising goal.
"Their cross came from our left back area across the six yard box and it was a goal. At this moment it is hugely frustrating. Peterborough was frustrating and today is frustrating as well. But it is part and parcel of football and we'll get on with it."
Asked about the penalty decision that gave the Clarets a 1-0 lead, Mowbray added: "I thought the penalty was comical. But I generally sit here and try not to make any comments on the referee. My general comment is that he gets paid to make decisions and that's the one he made. Whatever I say is not going to change it.
"But I would imagine the TV pictures will show whether it was a penalty or not and people will make their own minds up."
And finally" "If we'd gone out today, I would have been sitting here saying 'let's concentrate on the league'. But we're still in the cup and winning football matches is what creates the confidence to win the next match.
"I don't know how many games it is since we lost at home and the team can carry a bit of confidence and belief into football matches at the moment. Yet we are a bit deflated today to lose such a late goal. It's not ideal.
Clarets boss Owen Coyle was delighted with his team's performance, and so he should after we fought back so well when many of us thought it would be too difficult following the Spurs defeat.
"This is as good a result as we've had," he said after the game. "We were playing a quality team that won 3-0 in the Premier League last week. To a man, my lads gave everything they can and as a manager I can't ask any more.
"It would have been easy for the lads to feel fatigued, mentally as much as anything, after the disappointment of a Wembley final being snatched away. I just have so much pride at the way the lads have shown their character and desire for this football club, and for each other.
"I think everyone in the country expected us to come here and roll over, but that was never going to be the case. Anyone who knows me will know that I have unbelievable faith in the lads and we have showed that we are a good side.
"West Brom are in terrific form and I think, given the events of the game, a draw is the least we deserve. We went behind to a deflected goal three minutes into added time, after I saw a board that said two minutes.
"At half time it would have been easy again to feel sorry for ourselves, but we said let's used that as a motivational tool, and we did. We missed some unbelievable chances and Scott Carson made a world class save, but we ended up with five strikers on the park looking to get that equaliser and I am delighted we've been able to reward those supporters. They gave us that momentum to carry on and I know this group of players.
"I gave them Thursday off just to spend with their families and recap on what they brought to the Spurs game. They walked out with their heads held high and I said to spend the day having a good cry, or whatever they wanted, but to make sure that when they came back into my training ground on Friday they had a smile on their face and ready to go to work. They showed that again and some of our play today was magnificent."