“Rules say nothing about completing a full lap on them – only that they have to be used. “
Mattclinch is perfectly correct, in this statement, and Ned and Don are incorrect that Schumacher accomplished it only because the Stewards failed in ruling correctly.
There is no try to get away with it, or get away with it. Simply put, as Mattclinch stated, the rules do not specify any minimum number of laps that a compound must be used, only that each of the 2 compounds must be used.
As soon as someone DOES use this effectively to their advantage in a race-winning or really any podium finish, be certain the regs will be changed. Formula 1 simply can’t allow any such innovation or individuality. It is, after all, a ‘spec’ series.
[hint:use Webster's Unabridged to look up 'sarcasm' ]