Flicking hairs are the first line of defense for NW Ts, normally this will give them a chance to get away from the creature that is threatening/wanting to eat them. Ts often see us as something huge that is likely wanting to eat them. If flicking hairs doesn't work their next recourse would be threat posturing and then biting.
But You can use it to mean that it just isn't in the mood to be handled that day or either you are being too rough with it, and need to relax, and try another day when the Ts in a more receptive mood
And if I read this right, CRZ is meaning Costa Rican Zebra? This isn't a good species for handling, THey are very nervous and will flick and bite, and run away. Better to find a less nervous species for handling. These do make great display Ts
i handle my zebra regularly, here's my trick. if it is housed in a critter keeper, use the lid to coax it out of the enclosure by encouraging it to climb the lid and then walk onto your hand. mine doesn't shoot hairs anymore, but when it still did, it would shoot the hairs onto the lid and be calmer in my hand. good luck!