Mallet Finger

Around the beginning of October I noticed that my left thumb would not straighten. I can only imagine that I had injured my thumb playing piano. Foolishly, I ignored this injury thinking that it would get better over time. It never did straighten, so I went to a doctor around the 20th of December. I was told that I had mallet finger. They put me in a stax splint. I have worn this splint continuously for 3 weeks.

Today, after 3 weeks of wearing this splint, I had a followup appointment. The doctor insisted that I take the splint off so that he could look at it. Sure enough my finger still drooped. I was outraged at this because it was my understanding that the splint had to be worn continuously for 4-6 weeks. My thumb was allowed to bend for about half a minute. Does this mean that the healing process basically starts over? In that case I'm looking at additional 4-6 weeks again? I have another appointment in 3 weeks, in which I wouldn't be surprised if he wants me to take it off again, thus preventing it from ever healing. Should I seek a second opinion?