After scoring 17 points in 33 games with the Falcons, he was released from his P.T.O on January 22, 2010, to join HC Lugano of the Swiss National League A for the remainder of the season.

William returned to North America following the conclusion of the season with Lugano to sign a one-year contract with the Florida Panthers on July 2, 2010.

[8] With the NHL lockout coming to affect, Thomas was assigned directly by the Avalanche to AHL affiliate, the Lake Erie Monsters.

On June 24, 2016, having left Modo as a free agent, Thomas agreed to a one-year contract with Austrian club, EC Red Bull Salzburg of the EBEL.

[12] After spending a month with Ilves, on January 2, 2018 he was introduced as a new forward for German club Kölner Haie of the Deutsche Eishockey Liga (DEL).