So, Scott and Ted, in their infinite wisdom, deactivated Zeke and then left him out in the hallway where anyone could just switch him back on? I mean, Lucas or Lilah could easily get home early, and it shouldn't be too much effort to just drag him back into the room and toss him in a closet or something.
At what point was it stated that they're wise? Just because you're a genius doesn't mean you still can't make stupid mistakes or assumptions. They could have believed that Lucas or Lilah didn't know how to work Zeke; that even if they got home early, they'd have enough time to do what they needed to do; or that they simply felt that they had all the cards even if they got backup (arrogance); they may have believed that Lucas or Lilah coming home to an empty house would be more suspicious than one of the duo missing.
Or maybe they panicked. You execute your plan for three years, and a couple of days before you reach your goal your roommate tricks you out of your hidden base? They needed to ACT. They did. They were sloppy.