SNA
reading your version of events, I would suggest it is legal, but not necssarily in the Spirit of the FTL scheme.
Two questions you need to ask, though.
1. Is this regular practice, or a one off due to exceptional circumstances and
2. Did YOU consider your preflight rest disturbed to the extent that you reported for work unfir for duty?
In the case of question 1, sh*t happens. If your crewing department are regularly in the business of rejigging your day like this it suggests a problem in the department or a shortage of crew. If not, it's a crewing department doing whjat ever it can to keep a flying program together in difficult circumstances.
In the case of question 2. , what might you have been doing at 1410, if you were rostered to report at 17:55. In other words, would you have been asleep, to the point that the telephone call would ahve " disturbed" you?
I know the CAA generally do NOT consider phone calls to delay report as disturbing rest, bacuse it is NOT duty. Would you consider a phone call from your uncle during the same period to be a disturbance of rest?
JMC-MAN