No offense, but people joke about comping booze all the time when trains are delayed, and it's funny the first few times. Nowadays (after a whole six months on the road) I'm honest and I say it'd have to come out of my own pocket.
No offense, but isn't this begging the question. The question being why isn't someone authorized to do right by the customer when things go wrong?
A few years ago I boarded the east bound EB in MSP in coach looking forward to breakfast in the diner, or at least a cup of coffee from the cafe. The SSL had been left behind in Portland, the diner had a malfunction that prevented coach passengers from patronizing it, and it took about 3 hours to decide that they would not be able to tow a broken own engine back to Chicago. To add to the misery (not mine), the air conditioner was not working in the BR section of the Portland sleeper in July. As God is my witness, a true story.
At some point, KFC dinners were distributed to coach passengers. I doubt the cost of the chicken came out of the coach attendants' own pocket.
Amtrak will under no circumstances give away free alcohol, unless it is meant to be included in the ticket, so Acela First Class. And you'd be correct that the KFC order wouldn't come out out the LSA's pocket, though if he/she forgot to document the expense on their paperwork and include the receipt, then technically they would own Amtrak that money.
The only thing I can "give away" without having to document it is non-revenue sized water, juice, soda, hot cups, or the plastic cups as well of course. Anything above that we need authorization from a manager (conductor doesn't really have say), and if it's an issue I'm taking care of for one passenger, then I really should document each item separately on a form for comping items, and get the passenger's signature.
Why? I don't know. I am just following policy. Way back theft use to be prevalent on the railroad, and now there is a huge paperwork trail to cut down on employee theft. Other than that, I really don't know what else to say.