Here is a comment Frank O'Connor replied to Louis Wu regarding Quick time events. We have seen some quick time events in video, trailers and vidoc's, such as the Chief climbing over some scaffolding/ wreckage, prying open door and the part where the Chief throws an Elite over a ledge. But the the questions is do we control those quick time moments or do they happen automatically like they do in Reach?
Here is the comment Frank O'Connor gave:
"I would point out these moments are rare and only happen during events that are things you can't normally do physically. The first level has a couple of them to "train" you, but they won't be frequent or presented as QTE problems. They're transitional or cinematic vignettes that don't yank you out of the action. Also, if you don't smash that Elite he tosses you down the shaft".
Original Link to Frank O'Connor's Comment Here