(note the 1/8 in the log but still 0/8 on the tracker)
at first i thought it was just lag, but i then went on to do another quest and it updated just fine, while that one remained at 0/8. when i went back to that quest, it updated to the appropriate number after i killed a second one(went srtaight to 2/8). so its not a major bug, but might be something to look into.