Corrected entry: Thomas and Minho decide they are going to go check out Section 7 after they find the creature they killed was from there. But Minho states that when the maze changes, a different section is open every night. Section 7 was open the previous night but they decide the next day that they are going to go to Section 7 to check it out. Then when they get there, Minho is surprised to find Section 7 open and states that it's not supposed to be open for another week...but that's why they went there in the first place.
Quantom X
2nd Aug 2018
Correction: That they are surprised by the fact it is open is not a plot hole. They had no other plan, all they had was section 7 and the fact the creature that came from it had died. They theorized something must have changed and they went to check that theory. They didn't know what they would find.
lionhead