User blog comment:Omega natsu2/Chapter 373: Let Live Or Let Die, Predictions./@comment-7418318-20140227145252/@comment-2214433-20140227151313

Sarutobi was unable to emotionally get himself to kill Oro. Even though his summon was yelling at him to go after him, he just sat there, probably cursing himself in his mind.

As for the mark, yeah, it was kinda stretching it. The clan was weird but the point was that till they received the mark, their ability was randomly activated. So if they took a night walk into a forest, enjoying chilly wind would've proven to be fatal.

The 'frozen' Kakashi thing reminded me of back then at Chunin exam when one look to his eye was enough to take Naruto (or was it Sasuke?) down.