Comment by loodish

Shorting the battery would probably cause an explosion in around one minute. That's close enough to simultaneous.

From https://www.mdpi.com/2313-0105/8/11/201

A puncture causes runaway/explosion in seconds. Overcharging takes 13 minutes. There's not good data on a dead short (because it's unlikely during normal operation), but it's going to be between those on the faster end. From personal experience a shorts cause things to get noticeably hot after about 10 seconds, the graphs show that once you hit 60C things rapidly get worse.

A relay may have been required to hold the short as the battery stops supplying voltage.