This is with latest z.sh as of this writing (b2d48e0). Reproduction:
$ rm ~/.z
$ cd foobar
$ cd ../fooqux
$ z -t
$ z -t foo
Yep, you're right, I'll get this fixed shortly.
ZSH USERS NOTE BACKWARD COMPATIBILITY WARNING!
Fix -t flag selecting the least, rather than most, recent matching
entry. Closes #68.
Fix confirmed. Man, that was fast!
z.sh is awesome, one of my top 3 all time favorite productivity tools. Keep up the good work!