Neofit;
Undoubtedly, your position is right when UAS event occured in a "shinning blue sky tempest".
But would you please consider that at 02:10 UTC, the vessel was flying in ITCZ (also called F.I.T - Front Inter Tropical in another language).
Many of us here have flown in that kind of weather, (light to moderate chop or turbulence) and we know that the pitch will vary slightly as will the thrust...in most circumstances not much but it will vary. The requirement to "set" five degrees in the checklist may not be exactly the result in the aircraft but it will be close, while the other crew member gets out the QRH and the PF. Five degrees is about 2 to 2.5 degrees above normal cruise pitch and perhaps prevents the airplane from descending if the drill required, say, "3deg" and not 5, thus preventing a possible overspeed situation from developing - it guarantees that the aircraft will at least climb and not descend. So there are some reasonable reasons behind 5deg providing it isn't held too long.
My "do nothing" view means roughly the following: Once aware of the problem, (and it may take a few moments), call the abnormal so the other crew member is aware you're aware and is alert for next actions, wait for a few moments, observe the altitude, get the FMC onto the GPS page and see if the airplane is climbing or descending and adjust pitch accordingly. In the Airbus at least, "thrust lock", which occurs when the autothrust is disconnected involuntarily, will prevent any change in the power setting. If the thrust setting was lower than cruise power when the autothrust disconnected, that will be corrected with the QRH pitch-and-power tables. In the meantime, control is maintained even if the airplane wanders a bit. It certainly isn't going to lose speed fast if the thrust is a bit low. But like the training notes say, get on with the QRH checklist smartly. The checklist provides guidance on how to ensure that the correct pitch and power are set and it takes a while as the settings slowly affect airplane performance and it stabilizes with the changes. "Do nothing" doesn't mean literally just sit there!
AlphaZuluRomeo;
Also I remember one fellow poster (can't remember who precisely, sorry...), who said as a captain he sometimes asked his F/Os: "look at me, not the instruments, and tell me without cheating what is our pitch right now" (aircraft in cruise). IIRC many couldn't say precisely.
It's a good exercise. But not being able to tell what the pitch and power was does not mean that all is lost and "5deg" is the only answer.
To me, it means leave the airplane alone. By all means do what is obviously necessary to maintain stable flight, but having to change something in these circumstances would be extremely rare. The energy state of the airplane was fine using the pitch-power settings just seconds before the event. Unless sudden and unexpected entry occurs into turbulence that is severe to extreme, the pitch and power settings which existed just before the event are going to be very close to, if not exactly what is needed in terms of temporary pitch and power settings while the other pilot gets out the QRH. If the airplane starts to wander downhill, gently squeeze the stick back a tiny bit and wait for the input to take effect. Tiny movements on the stick is key, regardless of the method used.
I agree that five degrees is safe, providing the crew response is timely. But I think destabilizing the airplane when it was fine before, especially when almost no one is practised at high-altitude manual flight, requires some careful thought.