Custom Boolean ParamConverter wrong behaviour

Attachmente files describes an sample application thats use custom boolean ParamConverter used with @BeanParam + @FormParam parameter. Cxf is returning false for Wrapper Boolean Object even when null is provided as value in converter. 

Libs/Impls like resteasy and jersey works correctly returning null for Wrapper Boolean Object. 

Is this expected or its a bug ? There is some workaround or way to force null without coercing to false when null is provided ?