This particular televangelist is a goofball, honestly. His theology is out of control. But in this particular instance, God used the guy to reach my friend who is now growing spiritually like a weed.
Another of my friends, a pastor, made a snide comment about the "Oprahfication" of society during a sermon at one point only to find out that one of Oprah's best friends was a member of his church. (She's now a former member).
I'm all for confronting error. It's vital to ministry (Matthew 7:14; Acts 20:29). But a pastor has to be very careful choosing his words in talking ill of a person from the pulpit. And from time to time the pastor needs to call out specific people for specific errors in a public way.
With that said, it almost never serves a pastor well to talk poorly about a person from the pulpit. Those words are almost always misunderstood or misapplied and should be spoken judiciously even when they're necessary. Always.
Watch your mouth, and your tone. My friend needed to know that the televangelist who led him to Christ was a turkey - but the four or five pastors who reamed the televangelist from the pulpit nearly drove this guy away from the church altogether.