How comes Miller hasnt got a mask/helmet at the very end of the main story?

[Acpolax]

After playing the two collonells DLC where you can see how Miller gets hold of the satelite maps and realizing that for some reason he isnt wearing a mask in an area that from my understanding wasnt free of radiation I thought a little bit more into it and it just seems weird.
I mean at the very end of the main story Artyom is driving the bus right to the railroad crossing where he suddenly passes out till he wakes up shortly before the Aurora drives by.
Before leaving the bus Artyom looks to the right and sees Miller without a helmet.
Whats weird about that is prior to this we see Miller sitting on our right with his helmet on and Kirill is telling the story about how Miller carried him on his shoulders and even tried to teach him how to drive which didnt work out that well cause then Miller aparently died. Kirill also said something like "Better leave them be when they get like this" which makes me believe Kirril didnt take off Millers helmet but who did it then?

I mean for the DLC situation I can kind of understand that Miller was just an Idiot thinking he doesnt need to wear a mask since he got some green stuff anyways (which he ended up giving to Artyom instead) but still the main story part just doesnt make sense to be honest.

...No mask ...I should have known

[cuss]

Miller was probably asleep or unconscious when Artyom started driving. Likely he took it off himself before he died, preferring to breathe fresh air (as dirty as it was) one last time.

[Acpolax]

But then again even the way it is described in the wiki: "He uses a dose of anti-radiation serum meant for himself on Artyom and drives himself, Artyom and Kirill out of the city. However Miller succumbs to the radiation in the middle of the road and dies leaving an injured Artyom to drive the van to the Aurora." doesnt sound like he was still alive when Artyom started driving.

[Acpolax]

Well hear me out,
you know there is a cutscene in Last Light after the Garden when we meet up with Kahn and Miller and the dark one said "this one is green and this one is yellow, tell him I am not a danger"
well Kirill uses green stuff to somehow stay alive.
Just think about it.

[cuss]

I hadn't read the wiki. maybe Kirill or Artyom took it off, if he was already dead then he didn't need it anymore. Or just maybe escaping air from the old windbag made it pop off.

[Acpolax]

Yeah I mean it is a shame this isnt a reference to the dark ones.
Its almost like something is missing, like its an unfinished game.

To me it seems like they had the perfect setup for a realy good twist in the two collonells DLC
but then they decided to make it just another spider lair DLC.

[Acpolax]

Yeah whatever its an almost 5 year old game so it wont get a content Update anymore and If there was any speculations about Millers helmet there would be something to find on the internet already.
Next Title in the series is VR only so I will not get into it and thats about it.
Have a nice day.

[cuss]

Next Metro should be out in a year or two. Have a good one yourself.