I don't see the need to use profanity.
The actual function of the light is or should be checked according to the book of words written by people who clearly know a hell of a lot more than you and your dad combined, mind you they only made the system!!
You are talking out of your rear, the chart that ALL mot testers have tells them that it is a TEEVES 2 system as fitted between 85-93, it then goes on to say how the test MUST BE DONE, thus,
Ignition to position 2, the ABS light must extinguish between 2 and 60 seconds, THE ENGINE IS NOT ALLOWED TO BE STARTED FOR THIS TEST.
Therefore the oil pressure warning light will be on and so the way you and your dad have bodged yours will the ABS light.
If you don't consider that you have done anything wrong, and your MOT testers license is not at stake, print his details here and I'll get the MOT INSPECTORATE to perform a free inspection on your car for you, as I did on the car I bought around 6/7 years ago.
I do take seriously safety related items, unlike your dad who may be inadvertantly/unwittingly trying to kill you, this is not a blown bulb, but something which any sensible road user would rather be right.
tabetha
ps I await his details, we'll see