Sorry but I don't believe there's a connection. Martin Higgins who married Mary Tully had a brother named Bernard so that wouldn't be another name for him. Martin Higgins was definitely born in Williamstown, county Galway in 1882 which is much too young to be confused with 46 in 1901. His parents were Bernard Higgins and Mary Fleming. His dad Bernard is from county Roscommon. It's very unfortunate that you can't find a marriage especially it's not very far back. I did a quick search on IFHF to see if I could find a marriage but like yourself nothing. To be honest I have been very fortunate in finding records and haven't had any problems except in one line of my family tree where I could only find a church marriage with no parents listed. I hope you find a clue sometime soon and regret that I cannot be of much help.