While noting he didn't want to speculate until the investigation was complete, Dorcy said something certainly appears to have gone terribly wrong.
"None of them should have started firing unless they were returning fire from a smuggler or whatever the perpetrator might have been," he said. "Unless they were returning fire at something like that, there shouldn't have been any gunfire at all."
Dorcy added agents rarely fire their weapons while on duty.
"Every time something like this happens, it creates a new training scenario," he said. "I'm sure they will dissect what happened there once they know, and they will probably add that to their training regimen."
The Border Patrol declined to comment about agent training.
Ivie's death marked the first fatal shooting of an agent since a deadly 2010 firefight with Mexican gunmen that killed U.S. Border Patrol Agent Brian Terry in December 2010 and spawned congressional probes of a botched government gun-smuggling investigation.
Associated Press writers Felicia Fonseca in Flagstaff and Jacques Billeaud and Bob Christie in Phoenix contributed to this report.