Freaky - maybe there's an additional clip or attachment feature on the left?
Could be an anomolly due to "family molding" (which we do all the time in the plastics industry.) One mold will make a left hand and right hand part at the same time. Makes sense because, after all, nobody would ever build 1/2 of a car, right? Then somebody loses 5 boxes of left hands in the warehouse and they order a bunch of left hands. I tell them "You have to buy them in sets, that's how they come out of the mold." Then they say "But I don't NEED the right hands" and we negotiate a price for several thousand left hands alone because my yield is cut in half and it's more expensive to run one side alone.
Fast forward 10 months or so and somebody finds the "lost" boxes. Now the buy calls and tells me they're out of balance and they need to buy 5 boxes of right hands. We then repeat the above conversation. lol