Poor quality tool from iFixit, but with a happy ending.
Getting the back open on my MacBook Air
I was able to use iFixit's 5-Point Pentalobe Screwdriver to remove the screws, but I have to wonder how long the screwdriver will last. We've all used cheap Chinese screwdrivers that had their tips break off after barely any use. The first clue is usually that the chrome plating flakes off after the blade is inserted for the first time. Well, that's exactly what happened when I inserted my new iFixit screwdriver into the first screw. Costing almost $20 (including shipping) you'd think they could make a decent product.
I later bought iFixit's "54 Bit Driver Kit". This "kit" is a well made tool. Every crazy bit Apple uses is in it. Pentalobe for iStuff, check! Tri-tip for MacBook battery removal, check! Normal tips, extra tiny, check!
I've used it for fixing many computers, and it shows zero signs of wear. Congratulations iFixit, you CAN do well when you try!
Shame on iFixit. Shame.
...well, at least *some* shame.