OMG! Perry, those links are boggling, especially the first one. I would not necessarily put credence in a witness saying he had seen the couple at another AirBnB post-disappearance--there are many instances of people (honestly, but mistakenly) thinking they've seen missing people--but the fact that it was THE SAME AirBnB Orbeso had actually, provably stayed at earlier in July is incredibly suggestive.
However, playing devil's advocate here--the neighbor witness could have, indeed likely did, see Orbeso earlier in July at the AirBnB, when he was definitely there--and then, post-disappearance (when the couple were very much in the local news), when he saw (perhaps) a vaguely similar couple, it might have triggered the earlier memory and he conflated the two images/memories.
If we reject the staged disappearance theory, the fact that investigators found four different hallucinogenic drugs in the couple's belongings certainly buttresses the theory that perhaps they were under the influence of something while hiking, and that caused poor or erratic decisions that ended in death.
Meanwhile, Orbeso's poor father keeps faithfully hiking and searching.

Q: How many therapists does it take to screw in a light bulb? A: Only one, but the light bulb has to want to change ...