Check out note from Eric Mastalir in comment section.LINK. Photo above courtesy of MileSplit.
The following is from Eric's coach, Walt Lange in what he remembers about that record performance.
"Eric got that time at the World Jr Championships in Romania. He finished 9th in the race and was the first non-African finisher. The winner ran barefoot. Eric ran the last 1600 in 4:20. He qualified for that final just two days earlier by running 14:02.05, which is still #2 on the California list.
Hard to make a judgment re how the mark compares with our other records, I'll let others debate that. But it is impressive--done in mid-summer several time zones away, not in the familiar setting of the California state meet."