No he isn't. Mel was 12 years old in 1968 when his family moved to Australia, and the draft ended in January, 1973, Mel was never in a position to be drafted, or to "dodge" the draft.
Gibson Sr. didn’t want any of his sons to have to serve-I think he had 6 or 7 sons.
Well Mel's father couldn't prophesy that in 1968 and he also has several older brothers.