In Flashpoint, how does Barry vanish before his mom could be killed?

Question

Look here for the video reference. In the Flashpoint, at the beginning of season 3 of The Flash, Barry Allen lets Eobard Thawne to go back to the fateful night and kill Barry's mom. Ok, here is the crucial part of changing a timeline.

The original timeline was changed by Barry at the end of season 2 by stopping Eobard from killing his mom (1:50). As a result of this event (of saving his mom) we see the Barry behind the door smiling (that his mom is now saved) and vanishing (2:11) because well, the timeline changed!

So, now we know that the timeline changes due to an altering event. (Pretty obvious, right?)

But when Eobard comes to kill Barry's mom again, we see that Barry and the other Eobard lying on the floor are both vanishing (2:37).

Wait, hold on! The new Eobard hasn't yet killed Barry's mom. So no event has yet occurred that could change the new timeline where Barry's parents are alive. Then how could Barry and Eobard (the one lying on the floor) vanish? This makes it easy for the new Eobard to kill Barry's mom without a fight from Barry. This is so not possible! No event occurred, so no erasing of timeline, and therefore no Barry should be vanishing yet!

What should have happened here is that the recent most Eobard and Barry, who agree that timeline needs to be reset come back to the fateful night and convince the previous Barry, who just saved his mom, to allow his mom to get killed or else fight him if he doesn't agree. Only after his mom is killed, should the previous Barry and Eobard (lying on the floor) vanish as only now the timeline is reset.

What am I missing here? Or is it that the show writers missed this plot?

Answer 1

Out of universe - If you want to get technical, each time we've seen the same event, it's been incomplete because they hadn't thought of the later iteration of the moment. See also how much more complicated Fry's accidental cryo-freezing was in Futurama, as each later story involved more people going back and affecting the moment.

You're also not mentioning the FIRST time he goes back to attempt to stop the murder - the Flash of that moment looks at him, and tells him to stay away. So there's a THREE-fold overlap here, with FOUR Flashes from various moments in his timeline.

1) Original events - Flash tries and fails to stop Reverse Flash from killing his mom.

2) Travels back "again" to try and stop it, original Flash stops him.

3) Goes back and successfully stops Reverse Flash, causing Flashpoint

4) Travels to moments after the events of 3, allows the deed to be completed by Thawne #2

In-universe - Consider what we theoretically SHOULD have seen in the list above. At no point do we ever see ALL of these events.

There's a remote chance that the Flash we seen in version 2 is actually from an even LATER point in his timeline, trying to go back further than before to sort everything, which would explain how he knew about "Flash #2" being there.

One could surmise that simply by going back to START the change to the timeline, some retroactive change to the events may occur. And since all we can really do is surmise, with no facts to use, that's what we'll do.

Another possibility is that the "Flash of the moment" only sees the other versions of himself for the instants that they're supposed to interact. So it may only SEEM like Flash and Thawne "vanished", when in fact Barry took off to get up to speed to make their return trip.

Answer 2

P.S. I undertstand it now. Just read this one. https://arrow.fandom.com/wiki/Time_travel#Dangers_of_speedster_time_travel It is even more complicated with speedsters.

This is rather complicated. But simply saying is that they are not "real". They are just time decorations, because the same person should trevel to the same time only once to avoid time vortex (exceptions are speedsters and with them rules are more complicated). They have no free will, if they process some new information, they immediately vanish. (Note, not erased.) Read this one: Why weren't there two Barry Allens in Flashpoint Season 3?

Barry merges in memories with his future self, the future self though slowly rewriting his memories when he use speedforse. Also both Eobard (!) and Barry's memories were restored when they travelled to the original timeline. https://www.reddit.com/r/LegendsOfTomorrow/comments/5zkfzi/why_eobard_remembers_solved/ (13 comment)

Obviously, if it was not the case, there will be paradoxes, like if they were to fight, that will probably ERASE the main later versions of Barry Allen and Eobard Thawne. Than again the same will happen, Barry will again ask Eobard to kill his mother, they go back, get into a fight, lost and erased. It could become a permanent timeloop, which will destroy the timeline and the multiverse itself. In Flashpoint Paradox, how did Flash saving his mother cause multiple unrelated changes in the timeline? (Note important moment from that link: It is specifically mentioned that events before Nora's death were changed as well, so it couldn't possibly be solely the result of changes to Barry's life.)

Answer 3

My answer: the writers probably messed up.

Instead of showing the latest/most recent Eobard just showing up saying "Actually she's not", they should have shown him appearing outside the house a few moments earlier (because he can time travel!) and then he should have stopped Barry from entering the house in the first place to save his mom.

side comment: This would have led to some more action, and more complexity to the story-arc, and the show-runners were probably not up for doing that. They probably wanted to wrap up this event soon.