However, City refused to accept defeat and fought back to earn a point courtesy of a last minute equaliser from Danny Haynes.
"We've had a few goals scored against us this season in the last minute so it was nice for the shoe to be on the other foot," Johnson said after the 1-1 draw.
"We could have felt sorry for ourselves when Forest scored so late in the game but we stuck at it and came up with a goal.
"We sent on a 6ft 7in defender to play centre forward and it helped us get the equaliser and I think we deserved it.
"For us it feels more like a win to come back and score and get something from a game that could have gone away from us but it's not easy to come to the City Ground these days.
"Billy Davies has got them playing really well and you have to come here and compete.
"I think we did that but there were not too many highlights in the game before the last five minutes."