You have put your thumb on the issue. When 3 ways are wired it is a good idea to verify that off is all down. All you have to do is flip one of them to make this true if it isn't. The "flip" side of that is they will also be off with both switches up.
These represent a logical "exclusive or".
0+0=0
1+1=0
1+0=1
0+1=1
This gets a little more complicated when you put 4 way(s) in the middle but you can still set them up so all down is off. Dr Boole says an even combination of "up" switches is off and an odd combination is on.
It always amazes me that an electrician will make sure all the cover screws are aligned in the same direction but they don't bother to coordinate how the 3 ways are set up. A lot of them just seem happy that they work right in all 4 states.
There is no code issue here.
