Anytime I notice any problem, I immediately bring it up in a clear, concise way. I always create indented bullet lists with specific callouts of the issue, like:

Orok Warrior:
– HEAD: The head is too big.
– RIGHT SHOULDER: The shoulder pad pokes through here.
– LEFT FOOT: He’s missing his toes.

The reason I do that is so each line will stand out on its own with its own unique identifier (HEAD, RIGHT SHOULDER, LEFT FOOT) instead of getting lost in a sea of bullet points, like this bad example:

Orok Warrior:
– The head is too big.
– The shoulder pad pokes through here.
– He’s missing his toes.

In a long list, it’s REALLY easy to skip over a line. The more unique each line is, the better.

The point I’m getting at there is, if he doesn’t get at it in the first feedback pass, you can immediately point to a named bullet point *that he missed*. If everything was made obvious in the beginning and he borked up by missing it, he’ll try harder. If he doesn’t get it on the third time, I’d tell him plainly: “I’ve pointed out this issue twice and it’s still not fixed. Will you make the change this time?”

It’s not rude or impolite… you’ve given him two chances already to get it right and he hasn’t. There aren’t any hard feelings because you did all you could to make it obvious and hard to miss, and the burden is on HIM to make it up to YOU. Also don’t forget… HE is working for YOU. :)

It feels like a more delicate balance than it really is.