The knee-jerk reaction is to say no, somebody will catch him.
"What is our knee-jerk reaction when we hear that a rich white kid was involved?"
I have no idea what the knee-jerk reaction against public regulation is based on.
He knew all about her knee-jerk reaction to the military and was trying to compensate.
This is a knee-jerk reaction that has no basis in fact.
And that's not a knee-jerk reaction to day's result, because i've been saying it for a while now.
"The first, knee-jerk reaction here to any question is to make a study."
"It was a knee-jerk reaction to a lot of media attention."
It was a knee-jerk reaction to pick up the phone that morning, she said.
Feel free to defend your knee-jerk reaction further, but you will still be wrong.
Idiome