Kodiak, there really is a long story. it happened in the morning, and we were on the road as soon as he was released from the clinic that afternoon, so we never learned much more.
We were at fisherman's bridge, down river of it a ways, parked in a lot, and he crossed a few hundred yards or so of ground to get to the river. The banks were obviously maneuverable to a guy in chest high waders, and the sandbar had vegetation. It was just past sunrise, maybe an hour or so, and the bear had obviously come in during the night. There was some traffic, the voices were carrying down the river, and he found himself trapped.
Don't know why he was there, maybe you're right about the carrion or kill. It makes sense.
But, as you can tell, it was trapped with it's back to deep water, and signs of people all around it. Dad went blundering right into the things comfort zone, and I'm sure it really wasn't so much surprised as just pushed too far. Dad reported that the thing came out running, and afterwards disappeared back into that loose patch of brush. So many unusual circumstances around it, but the biggest part of it was the fact that it almost certainly felt it had nowhere to go, and surrounded by danger.
If there hadn't been probably a hundred or more people within easy range, they'd have just blockaded it. The recon party came under attack. so, it was put down then. I imagine that the bear crossing the water, climbing the bank, and loping over the grass gave the guy plenty of time.
