While the Baggies' comeback had already started, Jermain's sending off was a key moment and of it, Brian says:
"It is a tough one, really, because I was quite close to the incident - their centre half is experienced.
"All credit to their player; you didn't think Jermain caught him but he has gone down and it has worked.
"He was upset and we all have to learn from that; you pick things up and that is something I am sure he will pick up.
"It is hard in this league; you have to adapt and adopt a certain mentality - some teams find it hard when they come down from the Premiership and it is difficult for us.
"It was mixed feelings for me, definitely; we started the game very well and then we ended up losing for the first time at home - but you have to credit them."
Brian is irritated by the suggestion in one newspaper that his signing implied West Ham are going to be a long ball team, and he adds:
"What do you want me to say to that? I have plied my trade up and down the country and in Europe as well so take that as you want it."
Brian knows it is going to be a tough slog to get out of the division and he adds:
"These teams are not going to roll over and die; we have to adopt a certain mentality to be able to close games out and certainly they came well back into it.
"I thought we were going to score again at 3-2 but it didn't happen."
As for Alan Pardew's view of the red card, he says:
"Jermain made a genuine attempt to play the ball and I don't think the reaction of the player was helpful; Jermain can think himself unlucky - he suffered from the professionalism of this game.
"Without a shadow of a doubt that was my most disappointing day as a manager; I was looking for leadership and character but we were cheap in possession and didn't dig in.
"I shan't forget it and it will live in the memory of everyone at this football club for a long time."