It is interesting to me that this would have ruined the movie for you. The alternative to him being a FedEx / UPS / etc employee would have been to make up an “Acme Shipping” company. I find that much more distracting. To me that telegraphs “this is a movie! it isn’t real!”. If a shipping company’s plane is going to crash its far more realistic if it’s FedEx / UPS / etc, since those are real. I hate it in film and TV where they’ve done unrealistic things to avoid product placement: it can be just as distracting as doing unrealistic things for product placement. I remember some sitcoms used to cover up the car logos with black marks when shooting in car scenes. It was really distracting, since all I could think about was how they lived in this made up world with black dots on their cars grills.
Also, as others have noted, I wouldn’t have counted this as product placement since it wasn’t paid. I don’t have a cite, but I remember reading FedEx was on the fence about helping out with the movie, but in the end decided it wouldn’t make them look too bad given the “act of god” nature of the accident. After all, it wouldn’t be a completely positive placement, since there are lots of scenes of soggy, undelivered packages