Villager Depositing Incrementally after construction

I just played a game Chinese vs French. I was Chinese and used 5 of my starting villagers to cut a tree. When they all had 10 wood I had them build a mill. After the mill was build, the villagers only deposited 15 wood instead of 50. I must have re-tasked them as they were dropping off the wood after the animation, but before the drop off was complete.

What I learned is that for some reason these drop offs occur incrementally. The wood first went down from 10 to 8 then 7, which is when I re-tasked the villagers. Not knowing that and thinking all the wood had been deposited I started on the sheep, which cause me to loose the remaining wood. Then when I went to make my lumber camp, 15 wood instead of 50.

I checked the regular drop offs after buildings have been built and villager was just collecting the intended resource. There was no incremental depletion even on 1/4 speed in the replay. However, for villagers depositing resources when making a new resource building, this is incremental.

This makes no sense. Please make resource drop off consistent for all types of dropping off.

Thanks @SuperZorg! There should be a fix coming for this in the next big update.