Don’t ask me
Definition 1 of 2
Pro Tip 1/3Expressing Ignorance
Use it to show you don't have the knowledge about something being discussed. 
Don't ask me how that works, I just drive it.
Pro Tip 2/3Avoid Responsibility
Suggest not to be questioned because you're not responsible or in charge of the topic. 
Don't ask me for the latest sales figures, I'm not in that department.
Pro Tip 3/3Deflect Inquiries
Deflect questions you believe someone else should answer. 
Don't ask me, maybe ask Sarah; she organized the event.