Alan Curbishley called for more professionalism from his West Ham players after failing to close out victory and allowing Kevin Nolan to earn Bolton a point in their relegation battle.
Curbishley's men were 90 seconds from a win at Upton Park but chose to attack in stoppage-time, allowing the visitors a last chance to give their small travelling support something to cheer.
Nolan punished them, prodding home when Lubomir Michalik flicked on Jlloyd Samuel's cross after West Ham failed to clear a throw-in.
'We needed a bit of professionalism,' said Hammers boss Curbishley.
'One or two needed to get their foot on it and run it into the corner.
'If it had been Bolton, (El Hadji) Diouf would have run it into the corner and attracted a foul.
'The last thing we wanted with a minute to go was a long throw to go in there with lots of bodies. It was a typical Bolton goal.'
Bolton had been putting pressure on the hosts after George McCartney had opened the scoring with an acrobatic volley in the 19th minute, his first goal in club football.
Danny Guthrie hit the post, Gary Speed went close after feeding off typical Bolton knockdowns, and Kevin Davies also skimmed the bar with a header.
Jonathan Spector also cleared off the line and when it looked like West Ham would be earning a place in the top half of the Premier League, Nolan struck to earn Bolton a share of the spoils.
'You think it's not going to be our day but they kept going and the jubilation you get from that point is terrific,' said Bolton boss Gary Megson.
'You have two choices - either the white flag goes up or you keep going. They certainly kept going.'
Megson is still without a win since arriving at the Reebok Stadium and Bolton remain in deep trouble in the relegation zone - but he took heart from the point.
Under Sammy Lee, Nolan found himself on the bench or out of position, while Speed's appointment as a coach did not work, but Megson underlined how important the pair are by lining them up in midfield where they fought to get Bolton back in the game.
'Footballers don't play for the manager first and foremost, they play for their families and then the football club,' Megson added.
'Your family stays constant, your football club can change, so that is what you're playing for.
'In terms of playing for the football club they couldn't have done any more. They ran themselves into the ground, they can pass better, cross better and finish better - but we can't show any more commitment or honesty.'
Megson had Nicky Hunt taken off with a suspected dislocated shoulder, while Hayden Mullins was added to West Ham's lengthy injury list.
The only consolation for Curbishley is Dean Ashton returning to training this week.
'We'll see what we've got for Saturday,' Curbishley said. 'It doesn't seem to be getting any better at the moment.'