The former England coach is under immense pressure at the City Ground and his teams shambolic defending in this game will not have helped him one iota. He certainly didn't hide after the game as he gave his thoughts on Forest's performance.
"We were rubbish on and off the ball," he said. "We couldn't play football tonight, going three up gave them great confidence, we conceded five and we could have conceded two or three more.
"We have let the whole club down and all the supporters who travelled to watch us. I feel for the supporters, it is unacceptable.
"After Saturday's battling performance I am shell shocked, but we've been conceding goals all season, not just tonight, we have tried different formations and different players.
"The inquest will go on over the next few days in preparation for Sunday. We need to get a reaction from the players so that we give the supporters a performance.
"Something drastic has to be done, everything will be questioned and looked at."
Whilst McClaren struggled to come to terms with his team's performance, Eddie Howe was beaming at Burnley's biggest win since he took charge last January.
"I enjoyed that," he said. "I've been thinking that someone is going to be on the wrong end of a scoreline from us. Sometimes that doesn't transpire, but tonight it did and I am really, really pleased for everyone; for the fans, for the board and the players.
"The fans especially have been very patient with us and I really, really appreciate that. I know the players do as well.
"It's been a difficult start to the season and we haven't quite clicked. I think we've shown glimpses, especially on Saturday against Southampton, but tonight was the first time I think they have seen what we are capable of.
"There were lots of goals and we could have scored more. There are still areas we have to improve but everyone goes home happy. It was a big win for everyone and it gives us more belief in what we are trying to do that hopefully we can have a successful season.
"It is only one result, we have to remember that, but we have to look for consistency now. We should be looking up, rather than down and we are beginning to see the team spirit taking shape.
"I thought from the very off we were aggressive in our play and we moved the ball well. I still think we can do better, but on this showing we are going to be some team when we are fully integrated."
Howe had words of praise for Jay Rodriguez who finally got his first league goals of the season. "Jay had no need to worry himself. He's a top player and he will only get better and better," Howe said.
"He scored two great goals tonight and if you add his cup goals to his tally, he's not doing too bad. There's more to come though.
"His relationship with Charlie Austin is getting better all the time and Charlie was in the right place at the right time too. It's great that our strikers are scoring goals. They both have good tallies now and hopefully they can forge a really good partnership in this division."
Finally, he admitted: "The one down side was not getting the clean sheet. I think the back four is taking shape and we are beginning to look more solid. There were a couple of lapses tonight, but bear in mind what we are asking them to do is be brave and pass the ball out from the back."