Yeah, this makes sense
The evacuation of a smoke-filled passenger train in a Hokkaido tunnel Friday night was delayed by a company requirement that fires be visually confirmed before action can be taken, it has been learned.
The accident occurred on the JR Sekisho Line of Hokkaido Railway Co. (JR Hokkaido) in Shimukappumura. After its fifth car derailed and apparently caught fire, the Super Ozora No. 14 express train made an emergency stop in the 685-meter-long Daiichi Niniu tunnel Friday night.
JR Hokkaido's operation manual requires that train staff visually confirm a fire before any steps can be taken, but the thick smoke that filed the train and tunnel prevented such confirmation.
Yes, you're not seeing things. The explanation was that they couldn't confirm the existence of a fire because of the thick smoke.
I'm guessing that "where there's smoke, there's fire" doesn't have a Japanese equivalent . . .