Actually, the various extraordinary commands were not necesarily due to a risk of prosecution. I felt it was more for glory, than do avoid that risk. Think of Pompey; adored by the people, protected by his tribunes (who could veto legislation against him), he feared almost nothing.

The idea that the Invasion of Italy by Caesar was because of prosecution is true, although that was only the beginning. What Caesar wanted was for Pompey to lay down arms alongside him. He'd have gone to Rome, if Pompey had done that. Pompey refused, and hence the Civil War.
At least, that's how I see it.