The cynical part of me sees this:
Well a 2mm drill isn’t much bigger than a 1mm, so it should be okay. It’s all arbitrary so I’m ignoring it.
Hey, a 3mm is only slightly bigger than the guy drilling the 2mm. He isn’t complying so why should I?
Of course I had to use oil! Everyone knows when drilling steel you have to use oil? Not my problem it stains brass and plastics.
What the heck, an 1/8th inch really isn’t significantly bigger than all 3mm holes people are drilling and besides they aren’t enforcing anything anyway, if they can violate the rule why can’t I?