Ack, my sincerest apologies. I loathe when people speak in acronyms and assume you'll know. *sigh* Yes, I have to admit it... I loathe myself now. Sheesh.
OP can mean opening post, or original poster, depending who you are talking to, but it essentially means the same thing.
Ah ok I'm with ya now. No worries, I'm just a little slow on the up take tonight.
Two things here, starting with the OP.
Some group of 87 people living as a tribe in very dense canopy combined with being within a native reserve, having little sporadic contact with the larger tribe they splintered off of, is a lot more like some people living in the wilderness far far away and actively avoiding people as a group in a specific area that is not very likely to be examined too closely is not too difficult to avoid detection, than Bigfoot. Which according to legend is scattered all over North America and Mexico, living solitary lives in perhaps the most examined and explored continent in the world.
The case of the people in Earth As One's post happened in the 1800s. Long before the advanced technology we have now sweeping every inch of the planet from space. For the time, I would not make the claim that it's most likely they could not go undetected. But this isn't the 1800s, it's now and there are tell tale signs that people are living up there in Thule Greenland and they would be hard pressed not to notice the aircraft filling the skies each day.
As well since that time the worlds population has doubled, twice from around 1.5 billion people to over 6 billion at this point. There are many more people to see and many more looking.
And so while it's possible for Bigfoot to exist, there has never been a single shred of hard evidence to prove such a thing actually existed now or ever.
And so to answer you question, If you can remember what it was after this long way round, neither. Both the OP and Earth As One's post are believable in their likelihood, but have no comparison to the existence of Bigfoot. And so can not be used as an argument as such.