The dog has the most stunning blue eyes you can imagine. It's virtually impossible to not stare at them, and I've noticed otherwise extremely experienced dog handlers approach the dog for the first time, establish direct eye contact with him, and continue to stare into his eyes, even as the dog bares his (unusually long) teeth.
Imagine a dog that has been "stare challenged" by every human it ever encountered!! I've related my theory to others who find it obvious afterwards, but when one is looking at the dog, one's entire focus is on those icy blue eyes....
Good observation-- it does seem to be a pretty sound theory.
A complete aside here-- Ours doesn't have the blue eyes (many, but not all, do), but she does has the blue merle/leopard coat markings. When we first adopted her from the shelter, I kept finding myself staring at her because she's so beautiful. Even though it wasn't a direct staring into her eyes, I have to say she didn't really like it much! I still find it hard not to stare.
Good thing she's mellowed a bit over the years... :-)