Alien: Covenant - 15 Blunders That Ruined The Film
12. David Wipes Out The Engineers
A flashback eventually reveals that David wiped out the Engineers by "accidentally" dropping a payload of black goo ampules onto the surface of their planet, but as cool as this scene seemed in the moment, it was actually a pretty baffling revelation for a number of reasons.
Firstly, it was pretty clear from The Crossing prologue that David's claim to Walter was most certainly not true, and he indeed released the black goo intentionally, killing almost any suspense or intrigue this exchange was to supposed to have. And even if you hadn't seen the YouTube clip, it wasn't exactly a stunning reveal.
More disappointingly, though, this flashback does away with the Engineers, arguably the most interesting aspect of Prometheus, inside of two minutes flat, leaving audiences with a ton of answers about them and their hatred for humanity that will probably never be answered now.