“Can you say accessory?”
Unfortunately, as I understand present law no. But the problem is, where do you draw a line?
It is a tough problem. Consider all the cases where somebody holds a grudge - at what point do you criminalize holding a grudge or attitude? Reflect on all the domestic violence (do you know somebody who doesn't get along with their spouse/other half, and has a temper control problem?), employee/employer difficulties (imagine how many people detest their boss), road rage, "stole my girlfriend" cases ...
Add to the calculus, criminalizing a failure to pipe up creates a mix of perpetual clam up and over-cautious reporting.