What does hindsight mean?
: perception of the nature of an event after it has happened In hindsight, it’s clear there were alternatives.
Which pronunciation of either is correct?
Using English phonetics, [ EE-ther ] and [ AHY-ther ] are both correct. As a side note, giving “th” a phonetic Z (or S or F or D) sound is a common mispronunciation that can be corrected with practice.