I'm pretty sure the difference is on KoL's end.
Usually in KOL when you cannot use a combat skill any more it no longer appears in the skill drop down. When that happens mafia greys out the corresponding skill button.
In this case it appears that KOL is not removing the unusable skill from the skill box.
I'm updating the tag from Bug to Feature Request.
Feel free to reject the request, but this is definitely not a mafia bug.
if (get_property("_gingerbreadMobHitUsed").to_boolean()) {
foreach ss in $strings[stationaryButton1, stationaryButton2, stationaryButton3, stationaryButton4, stationaryButton5] {
if (get_property(ss)=="163") { set_property(ss,"");
}
}