I think overselling performances is a tactic most managers dabbles with. As Dante points out, if you admit that the team was shit, you put extra pressure on yourself and destroy what little confidence is left in the players. As a manager everything you can do to create some breathing space to do your job is a sensible endeavour.
Thus, I believe most managers thinks the optimum is to portray performances to be better than they were, but not to the extent that they look completely out of touch, or that the discrepancy between what is said to the press (and the fans) and what is said privately to the players become so big that they lose credibility.
I don't think McLeish is a particular culprit in this regard.
