That sounds pretty minor, If it was a huge glob covering his face maybe.
Paint errors on figures don't seem to be as popular as say hot wheels or misprints on cards or comics~Probably because most people like to have a figure as perfect as possible.
There is a number of people that do collect oddities though, I dont think the market is very big at all for them though & I dont think the Avatar Figure Line is very popular to begin with.
Just my thoughts, Don't base decision solely on me.
I know it is hard to open stuff like that though with the thought of any collector value lingering in the back of your head. I have a crimson dynamo I cant bring myself to open as the body is missing all black paint apps/wash + A WM Exc Cap that has mis-aligned print on the figure packaging inserts.