For being someone's core-intellect, Intellectual Ethan was pretty dumb.
What could possibly go wrong when you have Angry-Ethan or Psychotic-Ethan alone in a room with precious life-saving equipment?
Intellectual-Ethan should have just asked Alli to lock him up in a room and let him out only when he is Default-Ethan or Intellectual-Ethan. Especially when there had already been 4 sabotage attempts made by Angry-Ethan and Psychotic-Ethan - attacking the R10 machine, tearing out pages from the diary, and damaging the coolant pipes twice.