Banned Patrons how often?

I work for a small rural library today as I was at work today I found out that one of our regular patron is banned for 6 weeks. He is banned because he picked a scab and was bleeding leaving a trail of blood from where he was sitting, on the furniture and even on one of my coworkers clothing items. This isn't the patrons first time being ban but this is his last warning before being officially banned for life, he has had multiple times where he has done this same exact thing and my director did nothing expect give him warnings. The library had to throw out computer equipment and furniture because he bleed on it. So I guess my question is how often are these the patrons themselves the issue or the library management?