Technically spoken it looks as if ContentVersion doesn't return any node data of type binary.

Steps to reproduce (code):
1. create a mgnl:contentNode called 'X'
2. create a binary node data within X called 'B'
3. call X.addVersion(rule) with a rule that accepts 'mgnl:resource' nodes
-> version gets created correctly, also containing the binary (use JCR query tool to visualize the version node that you get when debugging X.getContentVersion("1.0").getPath())
4. call X.getContentVersion("1.0").getNodeData('B').getValue()
-> returns null, expected was returning the binary value of node data B

Steps to reproduce (visually, just quoting philipp here, please ask him in case of problems reproducing):
1. login to a fresh mgnl 4.3.6 instance, go to DMS
2. upload a document (binary, e.g. image), activate and evtl. accept the activation in the inbox
-> creates a version of that document
3. go to the version history of the newly created document and select the previously created version
-> no data is displayed, expected was seeing the image you just versioned

Philipp mentioned there could be a bug in ContentVersion aka. the ContentVersion$FixParentContentWrapper aka. ContentWrapper that fails to retrieve the binary from a node in the version workspace.