In the CDI 1.2 spec, it states:

When a contextual instance of a session bean is obtained via the dependency injection service,the behavior of SessionContext.getInvokedBusinessInterface() is specific to the container
implementation. Portable applications should not rely upon the value returned by this method.

However, it needs to specify what should happen when an EJB has multiple interfaces with conflicting throws clauses for the same method. The preferred outcome would be that CDI mandates getInvokedBusinessInterface and conflicting throws clauses work as expected.