Board Thread:General Discussion/@comment-6192846-20141209211951/@comment-7342272-20141224165219

Seing how Dashaw was Shaw's successor in the case of Shaw's death, it's possible he let him in on the secret, in case Elluka had to remain undercover after his death, so Dashaw could help them. Aware she wasn't family, he probably fell for her.

If he wasn't aware, then perhaps it a sort of familial love/loyalty that Elluka couldn't reciprocate since she was not actually related to him.