See this bug report for Lix: https://www.lemmingsforums.net/index.php?topic=4575.0
I have every reason to believe the same would hold for NL as well, except for that teleporters rather than wrap would be used to set this up. (Additional requirement: No updraft anywhere during the fall, as this resets the distance fallen counter to zero.)
This is of very little use in real world situations (not including teleporter animations, a lemming would have to fall for nearly 716 million frames - at which point it would survive the fall if it lands at any time during the next 716 million or so frames - for this bug to actually occur), but there's also little reason not to fix it as a "just in case" thing.
For obvious reasons, I haven't confirmed this bug actually occurs, but all theoretical considerations suggest it would.
Fixed in commit 785f07d.