3rd shot looks like it hit the deer in the neck. 3rd shot. It does look like you have a nice rifle set up that is probably capable of that type of shot, and I wouldn't have issue with it if it had been you taking the shot with your extensive practice at that distance, but to just plop someone else down and have them take a crack at a live creature at a distance they have never before shot at is a little irresponsible in my opinion. I'm not trying detract from your success in any way; I just think this type of scenario should be discouraged, especially if it's never before been successfully attempted.
Just out of curiosity, I did a quick ballistics calculation with a 150 gr.,7mm WSM bullet with a .498 B.C., and the 20 mph wind drift is more than ten feet. I'm not saying the shot isn't possible; I'm saying it needs to be taken with more caution and respect for the animal. I'm glad it worked out and that you had a good hunt overall, but I don't think this should be the norm.
One of the most honorable things a hunter can do is pass on a risky shot out of respect for the animal. I have shot and lost animals before for one reason or another, and it severely taints the whole experience, and you can save yourself some regret if you pass on marginal shots out of respect for the animal you're pursuing. Killing is a part of what we do, but it needs to be done swiftly, effectively, and ethically.