The situation is the following:
disc is thrown - travel call - pass is complete - travel contested without discussion - disc goes back
Question: Is there a check needed?
18.2.10. After a contested travel infraction where the thrower has not released the disc,
In this case there must be a check, because play stops. I am just wondering, why they mention "where the thrower has not released the disc" here. For me it implies that in the other case (thrower has released the disc), there is no check needed, which kind of doesn't make sense to me.
18.2.8. If, after a travel infraction but before correcting the pivot, the thrower throws a
completed pass, the defensive team may call a travel violation. Play stops and
the disc is returned to the thrower.
18.104.22.168. Prior to the check the thrower must establish a pivot at the correct spot
and, if a marker was present at the time of the throw, the marker may
move to mark the thrower.
Note: the plan is to amend this rule in the next version to make it clearer