Only problem is his honesty has been verified by the random sampling of physical bitcoins that have been opened and redeemed by presumably independent persons.
1 BTC coins 46/3836 = 1%
10 BTC coins 0/11 = 0%
25 BTC coins 6/249 = 2%
100 BTC coins 12/34 35%
I think we can be fairly certain that all coins that have been sold have been loaded with the BTC. If he were to load all BTC as expected, but keep a copy of the private key *that* is where a problem might be.
We can be fairly certain of nothing, considering 1) you have no idea who opened those coins, and 2) no smart thief would load none. I'd be happy to skim 1 of every 100 1BTC coins sold, for an extra $383 dollars.
Of course, practically speaking, the store has an incentive not to sell you food that will kill you, it's bad for their business. And they would also likely be liable for your injury or death. Every city in the USA is plastered with billboards for lawyers who would love to get in on the action if it ever happened. Those two reasons are good enough that you still patronize the grocery store.
I'm not a whole lot different.
Yes, yes. There's all kinds of legal avenues we can take advantage of to get back our stolen BTCs from you.

The fact is, anyone stupid enough to trust you like they trust their grocery store probably deserves to lose everything.