I'm only referring to experience vs. training in re: to a gunfight. Not all the other aspects of training, such as police training with regards to dealing with suspects.
After the training is all done, the mindset and performance under fire is still untested. Not so with those who have experience but It's still a contest between individuals.
Of course, some aspects of training emphasize cover, waiting for back up, and so forth. As far as the individual contest between participants in a gunfight, there's no difinitive answer to the question of which trumps which.