it could have been the exposure settings on your camera were set wrong, or the battery for the light meter could have been almost dead, or your camera is old and the shutter is malfunctioning, or the lens cap could have been on, or the lab could have fucked them up if there is stuff on the negs.
it's deff not a light leak, there would be evedence of it on every exposure. it's not old film either, that would make the colors look weird and would be more consistent.
oh, and its CAMERA not CAMARA