Bafang BatBoom

Louis Rossmann , Circuit board repairman of great repute, had his modded BBS burst into flame in NYC.
https://youtu.be/OEoZDpGFS7U
He internally shunted it and redid mosfets and appears to have had the battery go Samsung Note7.
Not sure if it was an Alibab bat of uncertain provenance or from other Chinese vendor
Follow up GoPro footage pending

He has a good takedown of his mods on his site with his repairs of earlier problem with discussion

should be fun to follow up and review for cause.
My hunch is bat was stressed and aggravated by shunt mods
He is wise in the way so we should get a good post mortem.

So few people understand how to properly spec a battery ( you need headroom in your discharge! ), and a lot of vendors overpromise and underdeliver on discharge ratings. Combine the two factors and you're gonna get

Let me guess.. he had a 30A maximum rated discharge battery and he operated it at 30A or more..
OR.. cheap battery with questionable interconnects ( common ) or improper padding/mechanical issues ( also common ).