But it didn't affect the ultimate outcome for King because he responded by winning the next races anyway - then wrapped up the day by finishing third while racing against the 450cc bike riders in the all-capacities champion-of-champions feature final.
This was easily enough to give him the MX2 title overall.
"The flag thing just happened so fast. I had committed to the jump before I'd seen the flag," King said.
"I came here really underprepared this weekend. But to come here and dominate is a very positive outcome.
"I enjoy racing the veterans' class, where I came up against my old mate Darren Capill. We've raced each other for years and it's always fun," he said.
Whakatane's Capill (Yamaha YZ450F) finished runner-up to King in all three veterans' races.
"I feel I'm getting faster each year," said King. "My aim now is to race just one more season and to make it a three-peat of consecutive MX2 titles, to go out with a bang."
The New Zealand Motocross Championships kick off just outside Timaru on February 10 next year, then head to Patetonga for round two a fortnight later (February 24), with round three at Pukekohe on March 10 and the fourth and final round set for Taupo on March 31.