"They worried about this, and were fairly confident in their calculations. " The problem with saying it this way, is that it's implied 'there was a risk but it

"They worried about this, and were fairly confident in their calculations. " The problem with saying it this way, is that it's implied 'there was a risk but it was within threshold'. There was no risk. It wasn't a thing. It's not like putting 100lbs in the elevator and knowing it will 'be ok' because it's way below the 1000lb threshold. It's not really 'safe' by calculation, it's mostly 'safe' by rationalisation.