For showing they would never use a shock collar (no value in it) but for field trails sadly many old trainers still use them. It helps the training process go faster instead of learning to work with the dog. Here are a couple of links you can read.
All field trials are sanctioned by some group such as The American Kennel Club (AKC), The American Field (the oldest - commonly called The Field), The National Shoot to Retrieve Association (NSTRA), and others. Most of the trials are held by local clubs with support from the parent organization. There are also championships and national championships which are club supported.
"Shock" or "E-Collars" may not be used. http://assi-cad.com/gbc/ftd.html
Here are a few other websites that talk about it.
http://www.hollysden.com/say-no-to-shock-collars.htm http://www.clickertraining.com/node/1021