A good thiller, with an inconsistent ending

Rating: 7/10 (9 December 2018)

This movie is a good entertainment. I love to see Denzel Washington acting and I love SciFi movies. But I have some reservations when a movie makes a turn at the end just to please the audience, to make everyone happy, even if it has to deconstruct the whole plot to make it so.
I think the movie should have ended with DW finding the terrorist. That's the purpose of the machine, to see in the near past and look once more for overlooked evidences, not travel through time. All attempts in this regard with living beings (guinea pigs) have failed, resulting in their death. What's done is done. It's sad all those people have died, but this is life. They had to die in order for the movie to make sense and to exist in the fist place.
But DW knows better and he goes back to the past, arrives dead but without any major (or even minor) internal injuries, is promptly resuscitated and becomes brand new again, fights the terrorist, saves the girl, prevents the ferry to explode and saves the day. But wait! Would the terrorist act had failed, there would be no need for using the machine in the first place, there would be no task force to join in and DW could not travel back in time to save all those people (and it doesn't even make sense since they're not dead). So, how and why did he travel back in time? It's a paradox.
I love paradoxes in time travel movies, but the script has to acknowledge this kind of potential situation and say something about it, not ignoring it completly. Ok, you may say that this happened in an alternate reality or a parallel universe, but there's no indication in the movie that this is the case. This ending was forged only to make it look happy to us, ignoring the consequences of DW's actions to the timeline entirely. It makes no sense at all.