To give you a short explanation, GoT was a very popular tv show.
There have been some minor problems here and there with the story throughout the seasons, but nothing major to piss most people in the fandom.
However, season 7 was filled with nonsensical and impossible situations. Same goes for season 8.
In season 8 (the final season), the showmakers destroyed pretty much every character in the show (by making them say things they woulld never say, do things they would never do, turn proactive characters into passive statues and so on… in other words, make them totally inconsistent), and on top of that there were plenty of nonsensical and illogical situations.
It was terrible not only, because it ruins any and all immersion, and no amount of suspension of disbelief could have fixed how terrible everything was. One would have to suspend his entire brain…
One of the most ridiculous things was, that after the episodes there would be a small segment, in which the showmakers would discuss the events of each episode and try to pull off some mental gymnastics in an attempt to explain how things “make sense” even though they didn’t.
In the particular episode from where the scene with the tribe that died had a trrible lighting and for the most part I couldn’t see anything. At least the showmakers clarified what happened (and later blamed people for having bad monitors or something, which was pathetic).
In the following episodes, it turned out that hallf of said tribe had survived somehow (despite the fact, that the showmakers said they are dead).
The showmakers were ridiculed so much on the internet, that they didn’t release a small segment explaining the final episode
Another example I can think of devs lying was the identity of the Arkham Knight character in the Batman: Arkham Knight video game. People guessed correctly, yet the devs were saying “Noooo, it’s not him”… and it turned out to be exactly who the people guessed.
So I would say, that StrikerJolt could be correct, despite what the devs might have said. I also thought this must be Rathma, given his power levels in comparison to his victims, as well as how tall he was.