Custom Relations Break 'Connections' tab

To recreate:

• Create a bespoke relation type. In our case it is a relation between a contact and a node. The relation has some custom fields.
• Use the relation select widget (as a field on the contact record) to add a relation between the contact and a node.
• Click the 'connection' tab on the contact record.

In all cases we get the following error:

"Call to undefined method stdClass::entityType() " on redhen_relation.module on line 197. Adding the following check above line 197 removes the white screen and the error:

if (!method_exists($related_entity, 'entityType')) {
  break;
}

But, of course, the relation is not listed as a connection. Which is fine. This particular relation is not really a connection as such. It seems like redhen relation should be checking to ensure that the relation is in fact a redhen relation before proceeding.