my personally opinion is that the sideskirts ability should only work when the unit is using the close assault ability, which is the logical, if not explicity stated interpretation, and was likely the original intent. Basically, that sideskirt keeps a soldier who is right next to the tank from putting a charge or sticky bomb (I believe anything that Tom Hanks says in a movie) right onto the vulnerable treads. It really wouldnt protect the same way against a bazooka or panzershrecht attacking from far away, or in a building.
I will grant the fact that sometimes the “official” ruling is based on the explicity stated wording, though it seems just as often, the “official” ruling is NOT based on the explicity stated wording. Has someone yet figured out why it says in the ruleback that a unit attacking a tank directly from the side is, i quote “neither in front of nor behind” the tank. What does that mean? It doesnt help anyone! Yet the official ruling states that attacking a tank from the side counts as attacking the rear. The people writing the text for these cards are not infalllible and might not anticipate the extent to which gamers will dissect the minutia of the rules to gain any advantage. Additionally, they might not anticipate every single possible combination of other existing cards and abilities, or cards and abilities that dont exist at the time, in order to include every imaginable scenario to their rule text. (For example, the trucks that can carry 2 units essentially breaking the hex stacking rule everytime they do so).
Regardless, the only way to actually find the actual answer to the sideskirts question would be to ask Avalon Hill. Anything else would just be our opinions, and a waste of mental energy.