Reuters has specific shipments and provenance for the pagers attributed now, and also notes that the explosions were concentrated in Hezbollah strongholds (Dahiah, Bekaa, southern Lebanon), lending further evidence that these were not off-the-rack pagers.

No one is saying these were off the rack or that they weren't distributed as part of Hezbollah's operation, so I don't understand how this is relevant.

The claim is that carrying one of these pagers is dispositive evidence that you are an according-to-IHL combatant.

The point I made is that less than half of Hezbollah is combatant, therefore the possession of a device procured and distributed by Hezbollah cannot be dispositive evidence as most Hezbollah members aren't IHL combatants. The fact the pagers were ordered by Hezbollah doesn't contribute anything in the context of a discussion on civilian Hezbollah members that would need to use pagers.