You should probably contact postal inspectors who'd watch that guy, but it genuinely sounds like a lazy as fuck carrier.

Some of them scan all the packages 'delivered' that aren't signature required and can fit in a mailbox in the van or LLV before they walk, so they don't have to bust out their scanner at every address.

So they end up having things scanned as 'delivered' before they hit the mailbox, and if they grab a wrong package out of the van or forget to grab a package, it'll say 'delivered', but it's sitting in the van... And then they look at the package in their hand and think "oh, this isn't even on this street lol" and leave without grabbing the right package... Or towards the end of their run they see a few packages with addresses they hit up earlier in their run and think "oh, forgot to deliver these lol" and they finish their run and go back to the station, only to maybe deliver them the next day.

I sometimes see that happen with my stuff... 'Delivered' on a Tuesday, then shows up on a Wednesday or Thursday, because the carrier is a lazy fuck. I'm a postal worker (not a carrier but I know exactly what a lazy carrier is doing so it pisses me off).

As for rewrapping your package, I doubt he actually did that - to go through the effort of finding a printer to print a label with indicia and all that - check your package and look at the mailing date and postage on it - if it has postage and the mailing date looks legit, and the tracking number under the barcode is the tracking number you got from MFS, and it isn't taped on and is applied to the package with the adhesive from the label, it's probably the legit package from MFS. I honestly don't even think he could make a copy of that label if he tried, so if it looks legit and untampered, chances are it's the legit and untampered package from MFS.

But in any case you should stick it to him for not delivering the package on the delivery date and acting shady with a package assumed to be yours on camera - www.postalinspectors.uspis.gov - management usually doesn't give a shit about carriers being lazy as they are at the station dealing with window clerks and people calling about other stuff - postal inspectors deal with this kind of thing - suspicious behavior from carriers.