I've decided to redo the entire bug report from here. Since apparently comments are NOT being read.
How to reproduce:
1. make a hole of 5x3x5 and place 2 water blocks in the top corners. These spots are marked with blue wool in one of the screen-shots. Try to make sure the water has stopped flowing into air blocks or else it might not occur. The block east of the sponge should be water or flowing water or it won't bug/glitch.
2. place a sponge in the center of the hole. On top of the yellow wool in the screen-shots.
Note that the water isn't absorbed/drained/soaked up.
3. Replace any water blocks removed for the retry, this should mean you have to replace only 2 water source-blocks and wait for the water to stop filling/replacing air blocks.
4. then place the sponge on the spot where the yellow wool is, notice that there had to be drained 1 block more and yet it drained 7 more. This has to do with the fact that there is no water or flowing water to the east of the sponge, which will make the results on the west-side become the same as on the east side.
In other words, there is more water being absorbed while the sponge has to reach more blocks and the sponge has to reach further and all that is just because of the block to the east of the sponge.
What I was expecting to happen was the same results on both situations OR an even smaller amount of drained water in the last case since you place the sponge further away and you have more water blocks.
There are of course multiple ways to recreate this bug/glitch, i chose this one since it comes closest to my original bug report.
I guess i will never write any comments again, they are useless if they are not being used.
If things still aren't clear, i guess the best solution is to ask me for a world download, although trying out a lot of configurations of water, sponge and wool inside this 5x3x5 hole should be sufficient.