why not "il n'est pas son premier disque"?
When être is followed by a modified by a modified noun, i.e., with an article or possessive adjective, use "c'est", not "il est".
record in French is different from record in English . do not confuse
that's true, yet another false friend. However, note that both languages use it in its meaning of "best performance in history". The Guinness book of records, for example, is edited in French as le livre Guinness des records
Ce n'est pas son premier dossier. :D
"Dossier" only means EN "record" in the sense of a set of files. Context makes that a bit of a stretch.
Maybe a first criminal record...
That's what i thought too. I was thinking of a lawyer's case record. Apparently this is referring to a rock star, not a law clerk.
Once more, there is no context so I thought it was referring to either criminal record or achievement record, not sound recording record. So this cannot be marked wrong.
Could we use 'à lui' instead of 'son'?
I think that changes the emphasis away from the possessive. Can a native speaker please confirm?