This might be a copy and paste error from the older games, but looking at the Evasion rules on page 235 of the Black Crusade rule book it says that "When Evading Full Auto or Semi-Auto Bursts, each Degree of Success on the Test negates one additional hit". Technically, as now just passing a check (for example, with a dodge of 50, rolling 41-50) generates a degree of success (Page 36-37 - Degrees of Success and Failure), this means that just passing would dodge or parry two hits, one for passing the check and one for the degree of success generated by passing the check.
Is this the way other people understand it or is this a mistake that needs an errata?