No one was in the building but them, so no.
Oh, as long as it is your own employees who get burned to a crisp, then it is fine, I guess.
Also how did they make a profit? They get paid the same if they just let the servers go down,
They failed to prepare properly. If they had DR, they would have simply switched over to their hot DR (or started up using a cold DR plan). Instead they tried to save their asses by relying on some people who either most likely weren't aware of the risk or also likely were digging all the attaboy's from their heroic efforts.
Nobody's physical safety was at risk if diesel fuel had not made it to the roof. But hauling open buckets with fuel in them to the roof up a stairwell is not responsible. Fortunately nothing happened, but that doesn't make it acceptable.