Wounding weapon and [bypass crit immunity] crystal

[King of Nowhere]

The wounding property of a magical weapon says that it deals 1 constitution damage; creatures immune to critical strikes are immune to this damage too.

There are weapon crystals to bypass critical immunity from some kind of creatures. The MIC has truedeath for undead and demolition for constructs; both those creature types lack a CON score, so there is no question. But similar crystals can be researched for other types of creatures.
Today the party fought elementals, and they had crystals equivalent to truedeath, except working on elementals (I'm not sure if they come from pathfinder or are homebrewed; either way, the description is basically "same as truedeath, but works on elementals instead of undead"). But elementals have a CON score, so the question arise: a wounding weapon equipped with this anti-elemental crystal would deal CON damage?
On one hand, the wounding property does not work on creatures that are immune to critical. On the other, the weapon equipped with the crystal can score criticals against the elemental.
Personally I think it should not work, because the creature is immune to criticals regardless of the fact that this specific weapon can crit against it. But my players argued in the other way, and there was enough of an argument to be uncertain. After a couple minutes, I decided to allow the wounding property to work for this fight - mostly because the party fighter was dealing low damage without it - until we could clear the issue.
Actually, this is a shady enough case that I expect there will be no consensus, but if nothing else, it can be an interesting discussion.

So, what do this forum think would be the best RAW interpretation of this issue?

[RNightstalker]

In the weapon enchantment's description, it says that "creatures immune to criticals hits are immune to the constitution damage dealt by this weapon." Finding a way around a particular creature's critical immunity doesn't change the rules regarding this specific weapon enchantment. I believe you are right.

[ShurikVch]

I, personally, would allow it for Plants (sap can bleed, right?)
But not for Elementals (they're too weird) I'm still baffled on possibility to wound an Air Elemental with a non-magical weapon (come on, what's you cutting with your sword? Air? So, does it leave any actual cuts?)