Breaking ties with call-ons

On page 332, in the bulleted "In Brief, it says the following:

*Call-on traits- Break ties or allow for a reroll on a failed test.

However, on page 330, when call-on traits are discussed, on the rerolling of failures is mentioned. Where does it explain how call-ons may be used for breaking ties, and if it is not explained, then how does it work?

The character with the call-on wins the tied versus test (by one, if it matters).

Does this count as it’s one use for the session?


Yes. It works exactly the same as in standard Burning Wheel.