(1) Team O now has possession. Because the disc was purposefully
dropped, it is a turnover by the defender after the catch. Rules that
don't apply include II.O (loss of possession due to ground contact
negates earlier possession) and XII.C (intercepted disc accidentally
dropped before or during ground contact is treated as blocked, not
caught and dropped). If the disc had been dropped accidentally or due
to ground contact, Team D would have possession.
(2) As an observer, I would give a TMF to the marker for this. There
is a dispute as to the outcome of the play (in or out of end zone), so
play stops. XVI.D. This isn't a continuation rule (XVI.C) situation,
as no infraction was called. This kind of behavior by the marker is
very similar to a marker who fouls, then blurts out no contest, taps
the disc (without it being offered for a check) and begins counting
again to try to pressure the thrower into panicking and throwing a
turnover (and failing to remember to object to the improper check).
(3) Yes. Foul.
XVI.H.3.a.1: A throwing foul may be called when there is non-
incidental contact between the thrower and marker . . .
XVI.H.3.a.1 Annotation: Nearly every instance of contact between the
thrower and marker will be non-incidental with respect to the thrower,
whether it disrupts the thrower’s concentration, interferes with the
thrower’s movement, disturbs the thrower's grip, interferes with a
throw, or affects continued play in any other way.
-Colin