Every style has a chink in its armor, everyone has varying levels of needs. For a teacher to make broad statements about the ability to address those needs, because they believe what they have is complete, without knowing of or understanding those individual needs is a huge red flag. With every style there is bias towards specific tactics & techniques. A boxer with rudimentary wrestling skills that are rarely reinforced may not be the best person to learn how to grapple from, simply because they have some knowledge. This is no fault of the style though, maybe it is a method that has a lot of grappling in it and the teacher just prefers boxing. The fault then lies in the man promoting the style as "complete".