I am guessing that you haven't seen his conduct record - you can view it online at http://search.archives.tas.gov.au/ImageViewer/image_viewer.h...
He returned to Tas and his Conditional Pardon was approved in April 1851. He would not have been allowed to return to England under a Conditional Pardon, however this doesn't mean that he didn't. His indent is not available online, but you should contact the archives office for a copy as they usually list names of parents/siblings/spouse. http://www.archives.tas.gov.au/reference
I have found two newspaper reports of his trial if you would like them, but the only family info is that he was from Wimborne Minster and married with two children (though his conduct record says one child) His sentence was commuted from life to 7 years. If you would like copies of the newspaper articles please contact me via the ancestry member contact and give your email address.