I'm not a t-ride local, but I've skied Bear Creek a fair bit. My understanding is that Chapman bought a thin strip of land that goes from one side of the valley to the other. The valley has 400+ vertical walls on either side. There is no road to the land and no motorized access. Hence, the land for development purposes is essentially worth nothing. However, if you ski out any of the backcountry gates into the Bear Creek drainage, you are pretty much committing yourself to briefly skiing across his land. There are exceptions for those on monster BC tours that could egress somewhere else, but 90% of people are going right over his land. It sounds to me that he saw T-ride trying to expand into that area with guided tours, etc and decided to take advantage of the situation. He bought pretty much worthless land surrounded on all sides by huge cliffs and forrest service land. Then he demanded that people stop skiing across it. The Forrest Service (not Telluride - they don't really have any say) decided to close the backcountry access gates to keep people off his property. I imagine that he's in negotiations right now with T-ride to see how much they'll pay for his sliver of property.
Again, I'm not a local and this is not fact, but I have spent some time back there and know the lay of the land...