I am sure the person who forwarded them was nice...but it's not like he had a choice. Most banks, and I haven't seen one that doesn't do this in a very very long time, require ID to cash a check. So unless they had false ID's made up to each name on the checks....
Also, most banks won't cash a check unless you have an account with them, just in case the check bounces, it comes out of your account. So unless they knew what bank everyone uses, again the checks aren't use.
And I certainly think that any bank would throw up a red flag over someone trying to deposit a check into their account with someone else's name on it. So all they really could do was throw them out, send them back to the USBC, or send them to you. It was very nice of the person to choose option 3 which gets you the money the quickest.
He forwarded it to me after taking the checks out of the original envelope and putting it into a business envelope. So I never saw the original envelope. There was over $3,000 in payout in the envelope. Definitely tempting to those with a broken moral compass.
If it was a postal service screw-up, wouldn't the correct address still be on the envelope? Then the person receiving the wrong letter would just write "wrong address" on the front of it and the USPS could try it again.