I actually dreamt about this and thought it was a cool idea that hasn't been done before. If someone with some addon development skills could make this a reality it would be great.
Basically how it would work is for raid-leading purposes, you could search through the combat log after a wipe by typing in two spells or search terms and it would announce to /raid the time difference between the two spells.
An example is if a rogue said he popped cloak of shadows before getting a debuff, you could type into a GUI after a wipe "cloak of shadows" & "nasty debuff" and it would look through the combatlog and announce 1 line to the raid like
"[Cloak of Shadows] was used by MrRogue 1.78 seconds after [Nasty Debuff] was applied."
Maybe you don't have to type the entire spell, you can just type "shadows" and it will do like a regex string search or something, so you don't have to spell the entire word out (dont know if possible).
It could also have other uses before a player dies I suppose, you can see the time difference between a heal on them or a specific cooldown they used and the time they died. But the possibilities are sort of endless depending on encounters that could come in the future.
Oh and in my dream I asked the guy what addon he was using and he said it was called "Hexany", not that that matters but feel free to use it if you want, LOL.