When I activated the Dump Truck for Dump Truck task, I was automatically given both new CAT trucks (dump truck and forklift) in my garage. Upon completion of the task, I was given a 2nd CAT774G as the reward for doing the task. It was nice to be able to test drive the forklift without buying it, but I presume I was not meant to have it given to me like that. And the duplicate dump truck gave a nice 160k boost to my bank account, though I didnt really need it.
@FearedFox18 It actually gave me all sorts of alerts when I activated the task, saying both trucks were now unlocked and both trucks were available for purchase, which is when I went back into the garage and saw I had them both as well and I did not see them in there prior to that (when I was choosing which truck to start exploring the map)