I own a rental business and I do not want to comment on who is right or wrong in this situation, but I do want to give my experience from a rental background on some of the comments and assumptions made in this thread.
Not all rental companies are bad, or good for that matter. Some have honest folks running them, and others do not. All rental businesses have a huge capital investment in their product with huge depreciation. Some renters take good care of the equipment, some abuse it, and some just have an accident.
My personal philosophy is I want to treat people fairly and I want them to treat me fairly. For some reason some renters believe that because they just spent a lump of change on a rental that they shouldn't have to pay for some damages and try to hide or not say they damaged anything. When I rent a machine I have the renter responsible for inspecting the machine and I guide them through the process. I tell them what I consider to be damages and what I consider to be wear and tear. Items I consider wear and tear are light scuff, damaged stickers, windshield trim pealing off, etc. Basically anything reasonably beyond a persons control. When a machine does come back damaged I take the customer out to the machine and go over the damages. We both inspected the machine before it went out and agreed on its condition and I show them the new damages. I also keep a damage log so that in the event that they question our checkout I can pull the damage log and look back over the course of the winter to see if that machine had that damage previous to the checkout. When I charge them I charge for parts plus labor to fix the machine. Now just because I charge someone there is no way I am obligated to give them the damaged parts or even to repair the damages as some have suggested. Here's why. Just because you cracked a hood doesn't mean I need to replace it immediately. You still damaged that part and depreciated the machine with the damage. If I am not replacing the hood you are paying for the depreciation of the sled. Additionally on items like a hood, if it is cracked I can run it and replace the hood prior to selling the machine. Then it looks much better for the sale. Now if a part is damaged that affects the performance, safety, or reliability of the sled then it is replaced immediately (can't say that's what other rental companies do). For the most part I personally replace all damaged parts with the exception of some smaller cracks in the plastics, immediately (or within a couple days) so that my machines always look good and the customer feels like they aren't renting a pile of junk. But I am not obligated to. I do also know that you can damage a machine going slow or without being thrown from the machine. Most of the parts on the snowmobiles are aluminum and if you hit it at the right angle even going slow you can bend a nun, a-arm, frame etc. It happens. Lastly if you are renting and you dent a bulkhead, put tears in the seat (even small ones), or bend a running board, then you should have to pay. Trying to sell a machine with those items is extremely difficult and you have to really drop the price to do so. So in essence, if you caused the ding, tear, or bend you should pay for the drop in price it caused. That is not simply wear and tear. Here's one other thought, if you are questioning weather it should be charged or not ask yourself this question, if your sled came back with a crack in the hood would you want the money for a new hood? Even if you weren't going to replace it? I had a guy bring back and ATV with a sliced sidewall in the tire. I told him that he had to pay for a new tire. He freaked out and claimed it should be wear and tear. I asked him if I took his truck out diggin and came back with a sliced sidewall if he would expect me to pay for it. His tune changed and he paid for the tire.
Sorry for being so long winded. But had to vent a little.