It’s not clear how many times Doctor Strange attempts to save Christine, but it’s implied through a montage that he exhausts every single avenue — including leaving her behind, letting her drive the car instead, and driving different routes. They all end in Christine’s death. The Ancient One tries to convince him after his final attempt that her death cannot be undone, because it is an “absolute point” in the Marvel timeline, something that cannot be manipulated.
Stephen’s ego takes over — which is why he winds up becoming a warped version of himself. But the Ancient One’s line about an “absolute point” has larger ramifications for the MCU. It confirms that there are things that cannot be altered and there are things that can. Fans already know that the Avengers slightly changed the course of history by stealing the Infinity Stones in the “Time Heist” sequence during “Avengers: Endgame,” which suggests the heist is an absolute point in time. It has to happen.
This episode crosses over into “Loki” territory as the live-action series explores what happens when someone deviates from the timeline — so it’s interesting that the Time Variance Authority didn’t try and intervene with Doctor Strange’s plan to save Christine in “What If…?”
It’s worth remembering that Kang (Jonathan Majors) references the universe has “crossed the threshold” in the “Loki” finale, which also sounds like an absolute point. It seems likely that as we get further into Phase 4, absolute points will become more prevalent — especially in films like “Spider-Man: No Way Home” and “Doctor Strange in the Multiverse of Madness.”