Form or function?
Who gives a shit if he uses is his delts to lift them. If he ends quite horizontal, his delts has to endorse a shitload of weight.
And it's almost impossible to do stretched lateral raises. Your weakest point is your elbow,
you have to bent your arms a little bit, which makes you use delts.
BTW, also doing raises with 62 and loving it.
The same story about the grip used with front-raise,
upperhand or neutral (and strongest).