A lot of words, many of which might well be true. But it ignores the fundamental point.
I think we can safely assume its not their building, not their datacentre.
As a result, they need to play by the rules of the datacentre operator.
The datacentre operator has fire suppression systems build to a certain spec.
The datacentre has risk assessments and insurance covers to think about.
The datacentre has other customers to think about.
The datacentre has its own staff to think about.
Yes, datacentres have some of the most advanced multi-layer fire detection and suppression systems in the world.
But a fire caused by multiple racks stuffed full of LiPo batteries will likely result in very hard to control results.
Yes, it is arguably highly unlikely to ever happen, especially with Apple hardware as you say.
However at the very least the guy should fess up and have a chat to the datacentre operator to at least give them a chance to say (preferably in writing) "ok, no problem, we'll just add it to our risk register".