this crew member as well as others (included me) reported for the stated on time on their rosters of 04:45z.
crewing department had revised the report time to 07:00z
crewing systems used for crew members to sign on states 04:45z
crewing department state that crew members duty start at 07:00z
flight deck paperwork is also states this.
the only bit of infomation we know is that cap 371 states that you duty sign on cannot change once you have left your place of rest!