I guess it goes with buying tractors, it's the dealers that make the product. Some of you have had experience with your snap-on, Mac or who ever dealer. I can only relate to a good friend of mine who has the reputation with the snap-on dealer that services where he works and I've watch him take in 20 year old air tools and walk out with brand new ones and yes the dealer did it on warranty. So I guess it depends.
Richard, Snap-On, MAC, Matco, etc. have some general rules you agree to, if you want to become a distributor, but basically the guy on that truck is an independent businessman. The companies have "manufacturer's suggested retail prices" for the tools and equipment, but that distributor is free to negotiate, sell below retail, take trade-ins, etc. The companies also have some rules about what they will and will not warranty. But the distributor may "warranty" something at his own cost. It would be unusual, but not unheard of, for the distributor to "warranty" something as expensive as an air tool himself, knowing that the company will NOT warranty it for him. Most of the trucks will take trade-ins on air tools and they usually have a table with the old traded-in stuff for sale cheap with no warranty. But when my brothers took trade-ins, they gave their customers a 90 day warranty, even on old trade-ins, but the company had nothing to do with that. And when my brothers sold a new toolbox, they always "threw in" a new impact wrench, or maybe something else in that price range that they knew the customer would like to have.
If the Snap-On distributor gave your friend a new air tool on "warranty" for one that was over a year old, then your friend was a good customer who spent a lot of money with that Snap-On truck.

But I guess you do know that the mechanics don't too often just pay for a new air tool. Instead, they make weekly payments to the truck. So for a $150 tool, the mechanic might pay $15 to $30 a week with no interest charged. So if you just saw him walk off the truck with a new tool without paying, that wouldn't necessarily mean it was warranty. I can also tell you there are many practical jokes played on each other by the mechanics
and sometimes with the tool distributor's assistance.

One will tell another that he got something free when he actually paid for it, or that he got something really cheap, or under waranty, etc. when it's not actually true.
At one shop with 5 mechanics, one of them bought a $5 cap from my brother while the other mechanics were not in the truck. Then he went inside the shop and told the others that my brother gave him that cap free. So the other 4 guys went out to the truck to see if my brother was giving away those caps and told him what the first mechanic had said. So my brother gave all 4 of them a free cap, then drove off before the first mechanic could come back out. Needless to say, the 4 gave that first one a hard time for a week about getting taken for $5 for his cap. Of course, the following week when my brother made his rounds, he gave the first guy his $5 back. But everyone had a good laugh about it, and yes, my brother was out five $5 caps that probably cost him $3 each, but he knew those 5 mechanics would be good customers from then on.