Rules Analysis
A Defensive Throwing Foul occurs when:
A defensive player is illegally positioned (Section 18.1), and there is contact with the thrower; or
A defensive player initiates contact with the thrower, or there is contact resulting from the thrower and the defender both vying for the same unoccupied position, prior to the release.
If a Defensive Throwing Foul occurs prior to the thrower releasing the disc and not during the throwing motion, the thrower may choose to call a contact infraction, by calling "Contact". After a contact infraction that is not contested, play does not stop and the marker must resume the stall count at one (1).
What:
A defensive player initiates non-incidental contact with the thrower prior to the act of throwing, but the thrower does not wish to stop play.
Result:
The thrower can call a contact infraction as per rule 17.4.1.3. If uncontested, play does not stop, but the stall count must be resumed at 1. Extra: The thrower may also choose to call a foul (rule 17.4) on this contact, in which case play stops. If the thrower accidentally calls "Contact" when the contact occurred during the throwing motion this should be treated as foul as per rule 17.4. Contact should only be called when the contact is non incidental -- e.g. it affects the ability of the thrower to freely pivot, fake, or prepare to throw. For incidental contact, the thrower may choose to call a disc space infraction.