It is often presented that if the franks lost the battle, europe would have been sacked by the muslims. How accurate is that?
The question has already been asked and mostly answered:
http://www.reddit.com/r/AskHistorians/comments/r79sf/is_it_true_that_if_charles_martel_had_lost_the/
In general, most historians believe the view that you are presenting is not correct - the Arabs were overextended at that point and did not have resources to take Europe.
A much more important battle in this regard was the siege of Constantinople 717-718.