O'Driscoll took over at Ashton Gate this week, less than a month after his acrimonious departure from Nottingham Forest, and for 65 minutes watched his new charges hold their own against a Leeds side who were barracked by their own fans for an anaemic performance in front of goal.
McCormack's second strike of the week changed the mood, though, putting Leeds on their way to a sixth successive home league win, a statistic that goes against the sarcastic cheers that have started to accompany every shot they have at goal.
They remain in touching distance of the promotion hopefuls, however, and manager Neil Warnock will now look to new owners GFH Capital to provide him with what he needs to try and close the gap.
Neil Kilkenny caused havoc in Leeds' box with a chipped free-kick early on and Liam Fontaine looked to have got in on goal until Sam Byram scrambled the ball away.
Leeds' first open-play effort, a 37th-minute shot over from El-Hadji Diouf brought about a sarcastic standing ovation from the home crowd, although they nearly had something genuine to bemoan as half-time approached, with Ryan Taylor denied by Paddy Kenny from 10 yards.
It took some brilliance from Kenny to keep his side in it immediately after half-time too, throwing himself to his left at the last second as Sam Byram sliced Richard Foster's cross toward his own goal.
After that it was a cocktail of errant crosses and ambitious long-range efforts from both sides, Paul Anderson going closest for the visitors, before Leeds carved a decent chance and with it a goal.
Loan midfielder Ross Barkley had been their biggest spark all afternoon and when he stood up a 65th-minute cross, McCormack made sure he got above Foster to plant a header past Tom Heaton.
There had been little to shout about before the goal and the game quickly reverted back to type, with neither side doing little to prove that the goal was anything other than a one-off moment of excellence.