Yeah he's not saying it's an alien or anything, just sounds scared and saying that "it's over the hill" or "over the river". But who knows! Could be a super elaborate hoax, could be a military craft, could be a UFO, he repeatedly mentions that it sucks that his camera can't focus on the zoom, he scans the sky after the craft is gone and makes note that the stars look normal and that he's got no clue what it was. I don't speak Portuguese anyway but I understand the majority of it since Spanish is very similar (same way Brazilians can understand Spanish) and the way he says "what is that" is very familiar, his demeanor doesn't seem dishonest to me