Interesting . . .

Sort of makes me wonder if the 1993 mix of ESB could actually be an exact reflection of a possible 'revised' 70mm version. It is said to have been taken from a 4-track master with non-limited dynamic range, and since it matches up with the 35mm edit of the film it seems possible that this is where that might have come from. This 4-track master cannot be an earlier version of the 35mm mix itself, because there are a few minor differences from that, most noticeably the missing snowspeeder crash sound, and also a few changes in blaster and explosion levels during the battle.

So . . . could it be? Was the snowspeeder sound actually missing from later 70mm theatrical prints, and this error got carried over to the 1993 version? Whether true or not it's still an unintentional mistake, of course, but it's a possibility worth considering.