Rules Analysis
Turnovers
If a pass is incomplete or if the disc becomes out-of-bounds other than as a result of a pull, a turnover results.
If the thrower accidentally drops a live disc or a disc in play without defensive interference and it contacts the ground before the thrower regains possession, it is considered an incomplete pass. If the thrower regains possession of an accidentally dropped disc before it contacts the ground without another player touching the disc, that possession is considered continuous . If the thrower regains possession of an accidentally dropped disc before it contacts the ground and after another player touches it, it is considered a new possession.
An accidentally dropped (falling, non-spinning) disc is not considered in flight. An accidentally released, spinning flying disc is a throw, not a dropped disc, and results in a turnover if the thrower regains possession of the disc without another player touching the disc.And the stall count continues uninterrupted.
A pass is intercepted if a defensive player obtains possession of the disc, but if the defender accidentally loses possession of the disc before or during ground contact related to the catch, the pass is considered blocked rather than intercepted .
i.e., this is not a "double-turnover" – the defender’s team still gains possession.