Probability of a Plague Marine getting hot

What is the probability of a plague marine plasma gunner being removed from play due to the "gets hot" special rule? Just for reference, I'm going to go through the quick statistics 101 calculation.

To "get hot", the marine needs to roll a 1 to hit. To be removed, the marine has to fail both their power armour save (3+) and their feels no pain save (4+). (Note that the feel no pain rule still applies in this case). So the probability of all that happening is

1/6 x 1/3 x 1/2 = 2.78%.

For comparison, a "normal" marine doesn't get the feel no pain rule, so they will be removed 5.56% of the time (i.e. twice as often).