"1st: I would give him the wrong bear back. Why would anyone want a bear rug that is not theirs? I sure wouldn't"
Seams reasonable.
"2nd: The Customer should be able to expect a certain level of service. Mainly their own bear done to a reasonable quality. Neither of these things happened."
For the most part I agree with you there but imagine if the bear had just slipped and not made it through the tan. Still no bear or quality or service. So what then????
"3rd: What the Taxidermist spent in time and materials is irrelevant. This is of no concern to the wronged customer."
Now that logic sounds greedy and self serving. The taxidermist and the client should always have concerns for all people. Now if you mean the lost money should not effect the value of the raw bear skin that makes sense.
"4th: In this case I do believe that a monetary compensation of some sort should be awarded to the wronged customer."
Okay I am not in disagreement with you there.
"This should, at a very minimum, be the price the bear rug was going to cost him."
Please explain this logic. I want to know how a raw lost bear skin suddenly is worth a finished bear rug???
"I could also see tag fee, gas, food, lodging, guide fee and any other costs associated with the hunting of the bear.
Is he going to get any of those extra expenses? No, but they are included in the valve of the raw hide to the customer."
He's not going to get those other expenses when you can go buy bear skins for a $400 and logical people know that. When your car gets wrecked you don't get the dollars for the amount of gas you had in it, all the times you washed and waxed it, money for all the times you had to get the registration renewed etc..... That's life and life doesn't change the value of the bear skin.