Thanks for posting the video. It usually looks like Karma determines who hits Deer and how bad the outcome is but in this case that little twitch you gave the right hand grip saved you and the wife a really bad one here. Looks like you made the bike kick left just enough to have a glancing blow. And I agree with the "loose all the speed you can" as soon as deer are seen anywhere in front of you. I find myself covering the front brake lever when I see a power line, creek or forest edge coming up ahead.
Always aim where you want it to go and never at people (DakarNick)