NRI return filling

TILL 2005-06 ASSESSE WAS RESIDNET FILLING RETURN IN INDIA

THEN FORM YEAR 2006 TO 2009 HE WAS NON RESIDENT (During this period he dose not filed any return)

THEN SINCE 2009 HE IS AGAIN RESIDENT (He filed the retunr for A.Y. 2011-12)( His only income is salary)

IS it offence that he did not filed return during the period when he was non resident.?

if it is offence or default, What could be consiquences, & what is the remedy?