Class A ground fault circuit interrupters (GFCI) are designed for the protection of personnel. NFPA 70E addresses GFCI requirements in more detail with the 2012 Edition.
This week's question:

Have you ever experienced nuisance tripping from a GFCI device?

• Yes
• No

Do you mean it was a nuisance that the GFCI did its job, or the reason for the GFCI trip was never determined?

Thanks JBD - I believe I need to clarify this a bit more. I meant nuisance tripping from normal operations such as starting a device like a saw, hair dryer etc. i.e. as you stated, the reason was never determined.

Sometimes when a motor operated device is on a GFCI circuit, the initial magnetizing current during starting (not the locked rotor current) can cause the GFCI to see enough of an unbalance that it nuisance trips. I have had several nuisance trips over the years with power tools on a GFCI circuit tripping. It is not a common occurrence but it does happen.

Beard trimmer in my bathroom.
Haven't felt any shock, so reset the GFCI and restarted the trimmer without any other incident.