incorret display of enemy cs

I had encounter this many times, it happens sometimes on laners too, but mostly happens to jungler.

I had the habit of pressing tab to check how the enemy was doing, so I realize that sometimes Enemy jungler's cs decreases compare to the last time I checked on tab.

It's obviously not misread by me, because there is no way for a jungler to have 2 completed items and only 8 cs.(this is real case i encountered)

I have no video nor screenshot and i am not sure what caused this, but this bug certainly exists, please take a look at it.