I heard at Toulouse a well-lubricated "Club high up" let it slip, amongst other thiings, that Daly is off because "he wants to play for the best side in England", and the driving force seems to be that his g/f is best friends with Farrell' g/f. The Club accepts that because he has been at the Club since he was at school, and they know that some players will always see greener grass elsewhere.
He also said that they were more upset by Hughes leaving because of all they had invested a lot in getting him his UK passport, treating his, mainly England, injuries and RFU "court costs", which they wouldn't be able to recover and other Clubs would get the benefit of.