[2ndround]

Generally speaking, he'll question why the package was claimed as nondelivered.

Does that mean that he isn't following company protocol, but is taking it personal and doing this in his free time because he is frustrated why I told them I received nothing?

I've read about drivers demanding SEers to fill in documents in which are written that they in fact did receive the parcel, does this actually happen and is this the case here?

The courier company can send a different person to check at your address and if you say no, they can send the original courier because courier companies can make the driver cover the loss from their salary.