The Gen 2 handled that Ike pull better than most of the many 1/2 ton trucks I have owned going back to the 1970s. Seeing the engine at 4500 rpm is not a concern at all, it could literally run like that all day long --- no different than driving a manual transmission truck up a grade like that and going into a lower gear to keep the engine rpm at the torque peak. The Gen 2 torque peak is somewhere between 4500 and 5000 rpm so the tranny did a great job of keeping it in the sweet spot.
I thought the truck did an OUTSTANDING job, the comments by the haters on the youtube page are just comical. The truck was composed, handled well, got great gas mileage, had plenty of power to accelerate at any time in the climb, managed the trailer weight without extreme squat or squirrely issues ---- other than limited engine braking going downhill, you couldn't ask for a better performance.
That test made Honda look really good, and it didn't cost them a red cent.