Unlike Denti, I think EU-OPS is quite clear - I wonder if you are mixing up FDP and Duty? One operator I worked for allowed 15 mins FDP after chox and then 15 after FDP end for Duty, two others said FDP ends on chox and duty at +30. Sub Part Q 1.1095 paras 1.4 and 1.13 is quite clear on the meaning of 'Duty' and 'Rest' and you cannot legally be 'at rest' if you are conducting duties for the company, which would include being in the cockpit after chox. The only 'get out' clause is 1.1090 para 5.1.1 but that requires the agreement of 'interested parties'.
What is of interest is that the CAP 371 '30 mins travelling time;' referred to by Beal has vanished with EU-OPs but time travelling from crew hotel to report is now 'Positioning' (1.1095 Para 1.12) and therefore 'Duty' (1.1195 Para 5.1) which could cause rostering havoc in some traffic jams!