The proper construction of s.611(2)(a) was recently considered by a Full Bench in Church v Eastern Health t/as Easter Health Great Health and Wellbeing (Church).  FWCFB 810 Church is authority for the following propositions:
(i) The power to order costs pursuant to s.611(2) should be exercised with caution and only in a clear case.
(ii) A party cannot be said to have made an application ‘without reasonable cause’ within the meaning of s.611(2)(a), simply because his or her argument proves unsuccessful.
(iii) One way of testing whether a proceeding is instituted ‘without reasonable cause’ is to ask whether upon the facts known to the applicant at the time of instituting the proceeding, there was no substantial prospect of success.
(iv) The test imposed by the expression ‘without reasonable cause’ is similar to that adopted for summary judgment, that is, ‘so obviously untenable that it cannot possibly succeed’, ‘manifestly groundless’ or ‘discloses a case which the Court is satisfied cannot succeed’.
And see Keep v Performance Automobiles Pty Ltd (2015) FWCFB 1956 delivered on – 23 March 2015 per Ross J, Wells DP and Lee C