If the marker calls a travel but the disc is caught, and the new thrower (who didn’t hear the call) then throws the disc away, is this a turnover?
No, the disc should go back to the thrower. By the continuation rule, play stopped when the offensive receiver caught the disc because the team committing the infraction retained possession of the disc (XVI.C.2.b.1). Once play stops, the disc is dead and therefore no longer subject to a turnover (II.R.3). The disc was subject to a turnover on that first pass, but not on the subsequent pass.
