Yesterday, I added a dedicated circuit to a bathroom remodel, GFIC. Due to physical constraints, the circuit breaker size in the panel box I had to secure the wires to the breaker before adding it to the bus. With the breaker off, wires secured I added the circuit breaker. I’m still alive, and the receptacle works fine.
However, for safety reasons, one is suppose to add the breaker to the bus, terminate the ground first, neutral wire 2nd, then hot wire.