What about a high public salary implies corruption? If anything, it would seem to be a signal in the opposite direction - a very highly paid police officer is not out to collect bribes.

Also, is there any inherent reason why police salaries should not exceed "physician administrators, investment managers and top elected officials" and other fields the article mentions? Also noted in the article is that some of these people are working ~30 hours a week average in overtime (70 hour weeks.)