phantom side mission?

hey all.
i am on my second playthrough of the story,i have done all side missions,but upon logging in today (10mins ago) i saw that there was a new side mission at the the botom left side of sanfran,i think it was called treating the wounded (or something there abouts)
anyway i tagged the side mission on my map and headed out,only when i got there it had disappeared and i can no longer see it on my map.

anyone know what this mission is and why it vanished before i could play it?

There are some rare emergencies that when completed give you a daily you can turn in for exp and rep with one of the factions. To my knowlege there are 3 of these.

it could well be one of those,but this was not a random encounter,it was shown on my map and had the symbol that shows it as a side mission..