A light twin will NOT go around from ILS minimums on one engine if you try you will crash if you are lucky it will be a soft crash onto the flat ground near the runway if not it will be an object that you cant clear because you cant clean up the aircraft and pick up speed or as you try to climb the speed drops off and you go below Vmca roll on your back and hit the ground inverted.
This is daft as a blanket statement.
There are many light twins that, at some or all weights, will go around quite capably from ILS DH on one engine -- some do so with rather more alacrity than a single doing a go around. To rule out the idea of a go around in all circumstances may turn a perfectly manageable situation into a an accident.
It's also undoubtedly the case that many light twins at or close to max weight cannot safely carry out a go around from ILS DH.
The pilot needs to know the performance that can be expected from the aircraft in the prevailing conditions and at the actual weight. Ignorance of that can lead to some poor risk management in either direction. Perhaps it did so in Oklahoma.