If you are with a rookie who's hesitant to blow the whistle, there will invariably be a few times where you have to go get something - either because it's too violent to pass on, or play is escalating out of control.
Go get what you absolutely need to get - our responsibility in the end is that no one gets hurt. Leave the rest. They gotta learn sometime.
As for the parent....think of an official you don't like, and use their name.