Pickup Question (needing urgent help after Ebay sale)

I recently sold an Electra Westone Phoenix (H/S/H) to a guy, who has wrote me claiming that the middle pickup is out. I used this guitar at several gigs last year and never had any problems with it. It was in perfect working condition when it left my hands. He claims that he tested the middle pickup and it does not work, yet I know that sound comes from the guitar in the middle toggle position. He agreed, but told me that the middle pickup does not work, and that the middle toggle position is getting sound from the neck and bridge pickups.

Can someone explain to me how this makes sense? I'm worried I'm being had here. If a guitar has a middle pickup, how could the middle toggle set off the neck and bridge in unison, rather than the middle pickup? I'm thinking it might have been re-wired? There's no way I could think of that the pickup that would be selected by the toggle is dead, so the guitar bypasses it and reverts to a normal dual humbucker toggle configuration. I know it's possible for the pickup to go out, but how would the guitar go from taking sound from the middle pickup to other two once that happens? Is the middle pickup cosmetic?

I hope I've stated my case clearly, any help would be greatly appreciated as I've NEVER had any problems with a buyer before.

UPDATEL He says the middle pickup on this particular model is activated by pushing/pulling the second pot. If this is true, fine. I do not claim to be an expert on wiring, but I have played this guitar with all three pots pulled, which I assumed was coil-tapping of course, and never had any problems. Is there any way this model gives sound from solely the middle pickup, or is it always blending with a humbucker?

there is not a setting for middle pickup only
you can only add middle pickup to the others
the 3-way switch is always active - neck, neck+bridge, bridge

the volume pot p/p is the coil split for both neck and bridge
the middle pot p/p is on/off for middle pickup
the last pot p/p is phase reverse for bridge pickup

Yep... what Mike said! The middle position on the 3 way give the inside coils of the h/bs, or at least it does on my H/S/H Spectrum LX and GT. 
Middle knob pull turns on the s/c...

Yup.

Excellent. Thanks guys. You all rock.