He should fix it or our friendship is over. A new bike too...
If he couldn't clearly do the job without damaging it, he shouldn't have done the job.
SG can you fill us in a little more on what actually happened? It sounds like it was actually damaged while unloading. Did it fall? Dropped? Roll off the ramp? Was it just him? Did he have help?
I know my thoughts went a little further than your specific situation, but my fingers had a little caffeine in them and would not stop typing...
I think Vabs has made a good point, and the bottom line remains how much do you value your friendship...the rest of the questions are pretty much so we can fill in some of the the blanks.
Wow that really sucks, if it was me i would right away offer to fix it. His actions are speaking for them selves, buy not speaking to you.
His offer of stickers is just revolting. I would like to ask him if i could just key his truck, and offer to put stickers on it.
How would he like that??
Sound like an over all bad situation, that does not have a good outcome at all.
I would say that you request your helmet back and be done at that point, he clearly doesn't value his belongings as much as you do, nor does he care how you really feal about this situation!