And although the disappointed East Enders trudged away knowing that they had come so desperately close to claiming victory, Wanderers wandered off claiming that a draw was the least that they deserved, after they had twice struck the woodwork and threatened Robert Green's goal on numerous occasions.
Ironically the Hammers' own late, late show at Coventry City on Tuesday evening had earned them a place in the Carling Cup quarter-finals and, returning to the bread and butter of the Premier League, Alan Curbishley made three changes as Danny Gabbidon and Nolberto Solano came in for Anton Ferdinand (hamstring) and Mark Noble (groin), while keeper Green returned in place of Richard Wright.
The lame Trotters had gone out of the competition following their home defeat against Manchester City in midweek and, with his misfiring 19th-placed side having recorded just a solitary win and three draws all season, Gary Megson made five changes for his third game in charge.
Still without seven-goal Nicolas Anelka, Megson recalled old-stagers Ivan Campo and Gary Speed together with Nicky Hunt, Kevin Davies and Ricardo Gardner in place of Mikel Alonso and Joey O'Brien, while Jlloyd Samuel, Stelios Giannakopoulos and Gavin McCann were all relegated to the bench.
Although Matthew Etherington and Solano had threatened with early bursts upfield, it was Campo who came closest to breaking the deadlock when he curled a 20-yard free-kick a whisker wide of Green's right-hand post.
But on 19 minutes, McCartney, poised on the edge of the six-yard box, went one better when he met Matthew Upson's nod-on with a spectacular, aerial volley after Bolton failed to clear Solano's inswinging corner.
And just two minutes later, the Northern Ireland International was the darling of the East End once more, when he nodded El Hadji Diouf's deflected, looping shot off the Hammers' goal-line with Green well and truly stranded.
Buoyed by that near miss, the Trotters continued to press and after Speed uncorked an 18-yarder that sizzled over the top, only the foot of Green's left-hand post prevented Danny Guthrie's low 20-yard shot from sending Bolton off at the break all-square.
Megson introduced Lubomir Michalik in place of Abdoulaye Meite at the restart and, after Hunt's long-ranger forced Green into a low save, Curbishley had to bring on Jonathan Spector for Hayden Mullins (knee).
With Bolton looked a different side after the break, Hunt and Speed soon forced Green to save their long-range efforts.
But at the other end, Jussi Jaaskelainen was still forced to turn the busy Solano's low 20-yard shot aside and then Gardner bravely denied Carlton Cole on the near post, as the pair raced in to meet Luis Boa Morte's byline cut-back.
Midway through the half, Etherington almost engineered the Hammers' second when he picked out Cole, whose low piledriver was parried by Jaaskelainen. before Gardner's came to the rescue again with his body-strength that forced the Hammers' attacker to nudge the follow-up inches wide.
Taking full advantage of that let-off, Bolton still went in search of a seemingly elusive equaliser and after Davies headed Guthrie's pinpoint cross on to the crossbar, Spector's goal-line clearance finally looked set to have preserved a Hammers win.
But that man Nolan had other ideas and, two minutes into stoppage time, with West Ham desperately hanging on for the final whistle, he calmly steered Michalik's flick-on beyond the despairing dive of Green to give Bolton a deserved share of the spoils.