I don't know what happened to these pant legs. 
These have the same number of rows.They were made on the same needles.
By the same person (me)
With the same ball of yarn.
?
When bad things happen with gauge.Obviously, I need to re-knit one of the legs. But I don't even know which one to rip out? Was I really tense one day and knit particularly tightly? Or was I really loose? Who knows.