The Glovers looked on course for victory when Ed Upson's speculative effort from over 30 yards squirmed through the legs of goalkeeper Adam Bogdan and agonisingly into the net.
Fortunately for Bogdan and the hosts, Alex Baptiste's goal in stoppage-time brought the teams level and earned the Trotters a point which moves them off the foot of the Championship table.
Johnson believed the cross which eventually led to the goal went out of play but was proud of the effort that his players put in on his 58th birthday, with the Glovers moving out of the relegation zone.
Johnson said: "It's like a broken record, every week we seem to get something where somebody makes a poor decision.
"The lads are pretty adamant that the cross was out of play, which is why a few people stopped because they thought it was a yard out of play.
"Don't get me into that again, please don't ask me another question on it because I'm just about to go home and slash my wrists.
"We've got to be careful that you don't get too carried away with being disappointed with a point at Bolton.
"We're disappointed because we were 1-0 up, albeit a mistake from the keeper. Having said that, I thought at that time we looked the most likely to score and I was very pleased with our play during that time in the game.
"We definitely took the game to them, we looked the stronger and we got the goal. Of course, they then go and leave five or six people up there.
"There was that little bit of naivety and hopefully we will learn quickly from that."
- Sports & Recreation
- Alex Baptiste