The convict John Roche is listed on the Fremantle Prison database as having never married. Also he did not get his ToL until 17 Jul 1854 - 8 months after Mary Egan married Joseph Rochez/Roches. Also he received a conditional pardon in 1858 when Joseph Packer was supposedly in SA. This is all very confusing...

ROCHE, John
Convict No 2544
Ship Name Phoebe Dunbar
Ship Arrival Date 20 Aug 1853
Birth Date 1830
Marital Status Unmarried
Occupation labourer
Literacy illit
Religion RC
Sentence Date 1 Mar 1850
Sentence Province Wexford
Sentence Country Ireland
Length of Sentence 10yrs
Crime burglary
Previous Conviction prev conv
Ticket of Leave Date 17 Jul 1854
Conditional Pardon Date 17 Apr 1858
Comments To SA 6 Nov 1866

http://www.fremantleprison.com.au/Pages/Convict.aspx