Nice, thanks for posting .I assume Eastwood's translation was prepared in advance.Of course he doesn't pronounce Morricone as an Italian would. Even if he could speak Italian, it would be strange for him not to pronounce it as an English speaker; it might even come across as pretentious.
Titoli, Clint is reading from a teleprompter. Everyone in the audience knows this so no-one would be making the assumption that Clint can speak Italian.
You're probably right, though I presume few watched behind their backs to see if a teleprompter was there. And still I don't think it would have made any difference to that audience if Eastwood had pronounced the name correctly.