I assume that oxidation is primarily a function of surface area exposed (times) the time it is exposed (divided) by the total volume of the wine, I came up with a little table to see if leaving the wine exposed in a Brute, while bottling for an hour or two is significant. To determine a factor of what I would consider a wine significantly degraded, I looked at a glass of wine sitting out for 24 hours. It had a factor of 384. I then looked at a bottle, that sat half full for 48 hours. It had a factor of 329. This just gives me an idea of a number that you do not want to be anywhere near.
Then taking my 30 gallon barrel, being transferred into a 44 gallon Brute and being exposed for two hours, while bottling, gave a factor of .4, or a 1000:1 ratio to the exposed glass if wine for 24 hours or opened bottle for 48 hours. So, I'm satisfied that there is not a significant amount of exposure while I bottle.