Bug? Skipped boss monster

[Reversedtime]

Not sure if I encountered a bug but I entered the Lumerian streets for the first time and saws a boss jump down from the sky. But there was also a save expedition flag point (flag 4) very near me and my health was low so I ran for it. I rested but now the boss is not there?? Did I accidentally skip it? Not sure if I missed any important storyline or loot by doing so,

[Gennesis]

No,you will fight him later

[Reversedtime]

Got it thanks!