Zack, I believe you are wrong about some facts.
The pitstop was most likely yesterday around ~16:45, as you can see in the photo here (put in spoiler to save space):
Show content
That means teams couldn't have arrived in Chamonix neither at 9 am today nor at 9 pm yesterday. And I don't know where you got those times from
Today the mat can be seen at the same square again from 9:46
Show content
to 11:01
Show content
, while at 11:16 the mat was already gone
Show content
. So that means under 1.5 hrs separates the first and the last team.