Of course he does and of course it will. Training for the 100 and 200 are vastly different from training for the 400m and are wholly different races, neither of which brings about much of a buildup in lactate. He'll need 1-2 years to knock 2.1 seconds off his PR (45.28 vs. 43.18 WR) and that's only if he dedicates himself to training the 400m.
He's commented before that 400m training is painful and he's not keen on doing what's necessary to run that race. I can tell you that training for the short sprints is nowhere near as exhausting, both mentally and physically, as what's required to be competitive in the 400m. As fast as 45.28 is in the 400m, that only lands him 8th place in the 2008 Olympics.