sensor position affected by away status?

I have a sensor network that gives me information about avatars inside a building.

During testing I noticed that some avatars who are "obviously" in one location are being reported as being on the floor above. The only hint I have is that they have their "AWAY" flag up. This alone seems to alter their Z vector position by 6-7 meters????? Is there something I'm missing about avatar "attachments" that could shift the Z position by this much, or is there an "adjustment" that needs documentation?

Maybe they have an attachment that plays an animation when they are away, and makes them appear beneath their actual location. At attempt to hide the avatar underground when AFK perhaps?