I don't know Owen Freeman, but I will vouch for the idea that seeking a bigger paycheck does not equal bad character. The vast majority of us have left jobs for better pay, sometimes multiple times.
As far as quitting goes, that's your opinion. All we know is that he had surgery that caused him to miss the rest of the season. It's highly unlikely that a player would have surgery that they didn't ultimately need, so the "quitting on his team" part comes down to the timing. Could he have played through it? Was the pain more than he wanted to deal with? Was he worried about aggravating it? We don't know any of that. And none of the potential answers to those questions automatically make him a "bad character" guy.
But even if he just wanted to shut it down to make sure that he was fully healed by the time transfer season rolled around, that's a business decision in his part, a decision that is replicated in the rest of the world all of the time without anybody questioning someone's character because of it. Only through the antiquated lens of College Athletics does that come into play.