Grout for Tumbled Travertine

Bought some nice 6 x 6 antiqued, tumbled travertine with the uneven edging. Wanted to go with a tight grout line but installer instead insisted on a larger grout for this stone - also used sanded grout - on a kitchen backsplash. Think the finished product looks good but think the lines are a little too big. Did he have to use the sanded grout on this??