Describe the Issue:

If you summon someone while they are using a flight path, instead of being summoned, their mount simply disappears and they fall to the ground from a height and die. 
If I recall correctly, I was traveling from Ironforge to Stormwind and fell off near Dreadmaul Rock in the Burning Steppes. Guild members talk about various places.

How to reproduce:

Summon someone while they are using a flight path.

How is it supposed to work:

It’s supposed to summon someone, not kill them :D

Character the bug occurred on:

Nazeth, but generally a lot of people from the guild are confirming the problem.