Jeopardy's Newest Head Writer

Jeopardy! has judges who are sitting in front of the audience. If Trebek is unsure of an answer he consults them (you can tell when he does this cause he'll look off to stage-right for a tick, usually holding his pencil in their direction).

If he gives credit for a question that he should have or shouldn't have, they correct him during the commercial break and adjust the score after the break (anybody who's watched the show has seen this).

In particular, if a contestant gives an ambiguous or incomplete response such that it's not immediately right nor wrong, it's up to Alex how soon to rule them wrong or how long to wait for the contestant to supply more information. Besides that, the host does have some discretion on whether to accept a close mispronunciation, and if the judges disagree enough then it will be addressed and corrected at the next break.