So the series started with a scene set later in episode 5, however I've noticed that the show has a habit of sneaking other future scenes in.
-- Hyun Su going into cardiac arrest: This scene was cleverly hidden at the end of episode 3. Basically during the montage at real BHS's hospital bed there is a quick glimpse of the doctors working hard to save an unconscious soaking wet Hyun Su which, should any of us have noticed it was Hyun Su instead of Hee Seong, we were to assume that it was the aftermath of being hit by a car in the rain. But in fact, it was hyun su being resuscitated after drowning.

-- Hyun Su running up to meet Ji Won: I haven't been able to find this one again,  but there was the clip of Hyun Su meeting Ji Won after coming from the human trafficker's office snuck in somewhere in the first 6 episodes. At the time I had assumed it was a flashback regarding the watch, but it turned out to be a scene from the beginning of the 10th episode.
(THIS WAS IN A MONTAGE AFTER EP 5, it also included the scene after Ji Won hears him say he never loved her, and her asking him if he loves her.)

has anyone else noticed future scenes that have come to pass, or scenes that don't necessarily seem like flashback which could be glimpses of the future?

If I recall correctly, the EP 5 montage also had scenes from EP 11. When she tells him to run away, and when she takes him home.

 Pro57:

If I recall correctly, the EP 5 montage also had scenes from EP 11. When she tells him to run away, and when she takes him home.

You're right!

I actually noticed that too. The montage from episode 5 had lots of those sneak previews, thanks for mentioning some of them here, @ForeverFanatic.

All of those scenes in the order they came up in the montage are as follow:

**The one from episode 8 when Do Hyun Su returns home and Cha Ji Won is waiting at the door and they have some bittersweet talk together.

**Episode 9 begins with a flashback to the time they got a new home and Do Hyun So had a suprise house warming party ready, it also hinted that "the scene when he tells Ji Won it's okay to open her eyes now"

**Episode 10, Do Hyun So running towards Cha Ji Won and pointing towards the watch on his hand "It's still a few minutes before 1 hour passed"

**Back to Episode 8 again, Cha Ji Won getting rid of evidence, hence burning even the recorder and Do Hyun Su's bag.

**The one Pro57 mentioned, Episode 11, Ji Won telling him to go some where no one could find him, not even herself.

**Episode 8, Ji Won overhearing the conversation between the siblings and leaving the scene, the latter scene is shown in the sneak previewing.

**Last in the sneak preview, is Episode 11, when we got the emotional hit. Do Hyun Su came back home and looked at the pictures of them three as family and crying out his heart (probably realizing how precious (not important) they are and he is so hurt from almost losing it!


I just want to say wow! Such a strong and beautiful MV that montage was, even from episode 5, all those scenes were hinted yet it was as unpredictable as ever, and it was crafted just so perfect! I was really hoping we will get some other episode ending with that kind of montage, this time hinting at the last episode! And episode 11 was the most likely, but it didn't happen yet. so I don't have an idea what's coming!

Indeed! The MV at the end of episode 5 was such a well thought thing!

Regarding that, the director has commented that he had two intentions behind adding the MV instead of a preview of the next episode at the end of EP5.
One was that episodes 1 to 5 focused on incidents, and the end of episode 5 marked a midway point. They wanted to send a message that from that episode on they would focus more on emotion rather than specific incidents.
And the other was that the impact of having Hyun Soo in a critical state in the ending was too strong. Therefore they thought that immediately showing him well in the preview would be uncomfortable and would "ruin" what they were going for with that scene.

I honestly can't stop being amazed on how much they think every detail!

 Lavy:

Indeed! The MV at the end of episode 5 was such a well thought thing!

Regarding that, the director has commented that he had two intentions behind adding the MV instead of a preview of the next episode at the end of EP5.
One was that episodes 1 to 5 focused on incidents, and the end of episode 5 marked a midway point. They wanted to send a message that from that episode on they would focus more on emotion rather than specific incidents.
And the other was that the impact of having Hyun Soo in a critical state in the ending was too strong. Therefore they thought that immediately showing him well in the preview would be uncomfortable and would "ruin" what they were going for with that scene.

I honestly can't stop being amazed on how much they think every detail!

That's SOOO cool! I did notice that 5 was the turning point for the series, where they broke away from the case by case format.

Okay, I just found out something else. That scene in the first episode, where they go for dinner with Hee Seong's "parents".... That face off scene at the restraunt gate had paintings on wall with deep symbolism. There was a youtube channel which broke that scene down. I don't agree with her fully, but she's onto something. Link : https://www.youtube.com/watch?v=v_hOY61DVdE