G550
The crew would have made their decision to depart based on their assessment of the risk involved. Whatever view you have of the risk involved would not be something they would know - or probably even consider relevant if they did.
And furthermore, for what it's worth, I think the risk of one engine failing on this acft on the climb out would have been negligible - and far from the greatest risk of the manoeuvre. And even if one had failed, I suspect a reject landing could have been accomplished, albeit with damage to the acft, but not occupants or property.