All the Dmax UOAs show 7.5k - 10k miles as doable, situationally dependent of course.
The only one that would make me a bit "iffy" is the LMM with it's post combustion regen injection, where the fuel may thin the oil, but even then the OLM tends to send a warning for shorter OCIs. That typically will not affect the guys that get up to temp and stay there, but the "short hop" drivers with no load can often see a lot of regen cycles.
The OLMs have been reasonably reliable in the Dmax trucks. Unfortunately for some of us, the OLM sneaks up on us because a small portion of trucks don't have the DIC controls on the steering wheel (mine is a W/T truck). I have no idea where the OLM is at until I get the 10% message.
Brettm1388, you cal tell your buddy that 5k miles is easily doable, and will probably under-utilize the oil. He's selected a very reputable oil that has shown outstanding capability. The LBZ is know as one of the best wearing engines. Have him run the 5k miles and then sample; he'll be impressed.