Yes the race did evolve perfectly for Cavendish. For one, they rode up Le Manie in group, instead of making the pace hard, like Bruseghin did last year.
Two, although the pace was hard at the Cipressa, there was no co-operation in the front group after that, thus the second group quickly returned.
Three, almost no attack at the poggio, normally they start attacking from the foot till the top. This time, nobody attacked until close to the top, you're never going to drop anyone that way.
So in conclusion, the cycling gods blessed Cavendish with an ideal race situation today, tactically the race was perfect for sprinters, because the attackers have waited too long. Cowardness caused the attackers to lose to the sprinters today, with Mark Cavendish as major winner