Oasis lvl 9 degrated to lvl 2

I had a strange thing happening when I just attacked a lvl 9 oasis with 1k cav.

There where 4461,482,95,233,soldiers

I lost 115 cav's and occupied the oasis, but when I looked it went down tot lvl 2?
Never lost so many cav's with a lvl 9 oasis attack

Is this a bug? Or is this somehow in the game mechanic?

Time of event: 2010-12-08 09:54:50 server 18

oasis level changes by +3 every day
so level 9 becomes level 2 (9 - 0 - 1 - 2)
it just so happened that it changed level during your attack, happens all the time

[Sylarius]

What the above poster said is precisely correct. This is no bug whatsoever.