Ephraim used a Mac. It says in his document...if I could find it somewhere.
Okay, I thought that was the case as well. This of course further confuses their list, as I'm pretty sure Dfoofnik reported PC Lemmings results under the addendum to Ephraim's list. In particular, I'm only aware of the DOS version giving you 20 builders rather than 10 in most other versions including the Mac.
I have actually dabbled a little on Mac Lemmings as well. I think the current status wrt to the Mac version goes something like this:
Tricky 16: needs to be confirmed whether 46/50 works on Mac or not, given the well-known difference (though it's technically a terrain difference arising from Mac's high-res graphics, IIRC) on Tricky 15.
Tricky 23: I think you might lose 1 or 2 more on the Mac due to one more mining stroke needed to stop lemmings lost, I don't remember the result I ended up with. It's certainly far better than 53/80 as the assertion "no way to save the ones that turn around" is wrong.
Taxing 6: I've fully confirmed that one on the Mac, you can save 49/50. You can use a falling exploder to take out the upper-right portion of steel, lowering the fall to safety.
Taxing 16: I haven't bother to execute the 100% solution on that one, but I've checked all the relevant game mechanics and they are all the same on the Mac version, so it should be possible on the Mac as well. This solution is glitch-free.
Taxing 27:
the sliding glitch The no-glitch lose-3 PC solution should work just fine on the Mac as well. The water doesn't reach high enough to affect the PC solution.
Taxing 28: the climber glitch used here has been confirmed to work on the Mac the exact same way it does on the PC, so the 70/80 solution likely works on the Mac as well. Although, one thing I might need to check is what shape you end up with for an interrupted bash stroke (again due to hi-res graphics). In any event, I first reported a lose-14 solution that doesn't use any glitches on the PC, so that solution likely works on the Mac too and is still better than the list's.
Mayhem 2: sliding glitch again, so should work.
Mayhem 10: sliding glitch for the lose 2 solution, should work depending on the interrupted bash stroke (see Taxing 28). Even if that doesn't work, we've found lose 3 and lose 4 solutions that use other behaviors which also work on the Mac.
Mayhem 26: this one is special because terrain differences (hi-res graphics again) on the Mac forces notably higher usage of bombers compared with other versions, making it nearly impossible just to achieve the 72/80. So I'm not 100% sure yet what the record should be on that level. I can tell you though that on other versions with lo-res graphics and only 10 of the 3 given types of skills, you can still achieve lose 5 (as confirmed on eg. SNES).
Mayhem 29: the PC version relies on a glitch and the lack of water. However, the Mac version allows better bridge-stretching facing left, so the "build west" route actually still works on the Mac even without using the glitch and with presence of water. So depending on how much builders you need (and thus how many spare left), I think you can still do something like lose 3 if not lose 2. Will need more testing to confirm.