Oh, that's what you're looking at. When they changed the tables and included 14-104 they didn't seem to consider other rules, like motors and heaters, although the rule specifically says "other rules". Maybe they decided that it was okay to load wires to a higher amperage if the load is a motor or heater; or, they might not have been able to imagine someone writing a rule that didn't increase the cost of an installation.
Think of it this way: At one time, #10 r90 was acceptable for a 40 amp breaker on a range. I worked on a really old installation and there was only slight heating of the neutral bar. Additionally, I was in a row housing complex that was wired recently (recently to me) and I reported to the inspection department that the entire complex had ranges wired with #10 on 40A breakers and they didn't do anything about it.
I'm pretty sure the inspectors know you can run #10. Get the permit quick before the new book comes out.
