David was sent off for a second bookable offence when he was deemed to have fouled Danny Butterfield but David says:
"I was a bit disappointed and I went to see the ref after the game.
"It has cost us the match and I feel so guilty - even though I don't feel the second one was a booking.
"I have closed down with aggression and pace as you need to do as a team, and I think he has just kicked my foot because I definitely didn't touch him - it is not my game to take players out like that.
"The angle of approach means I couldn't have kicked him anyway because I came in to block it when he kicked the ball, albeit at pace.
"Maybe that makes it look even worse but there is no way I have gone to kick him there and, as I say, I think he has kicked my foot.
"You have to close quickly, that is the game; you have to keep that tempo high and close players down quickly and with aggression - but I definitely didn't kick him.
"He has gone down because he has booted my foot and maybe that has hurt him; I know I felt something on my foot.
"If he kicks my foot when he is clearing then so be it - but it doesn't mean it is my fault.
"I am just disappointed for everyone at the club and the fans coming all that way - and it is all spoiled by that.
"Let's just hope the ref looks at it and changes his mind but even if he does it has still cost us two or maybe three points.
"To be honest it seemed that in the second half there weren't many yellows for things that maybe there should have been and in the first half there was a yellow for everything."
Several West Ham players made the point that the linesman, who was closer to the incident, did not flag for a foul, and David adds:
"The linesman didn't have his flag up and when I asked if he gave it he just blanked me.
"The ref said he was going to look at it but it depends what angle the video is from; hopefully it will be at the right angle.
"I definitely didn't kick him and maybe he has hurt his foot but that is not my doing.
"Obviously I have to take some responsibility because the lads have played three quarters of the game with 10 men and it is bitterly disappointing.
"Obviously I am gutted for the lads having to put up with 70 minutes with only 10 men.
"They have had to work their socks off for three quarters of the game with me on the sidelines - that is down to me not being on the pitch, I am sorry for them, and I apologise for that.
"I am disappointed for the fans and everyone associated with the club - everything we have worked for all week has gone up in smoke."