On 26 May 2015, the AFL launched an inquiry into Betts' signing with Adelaide after the outgoing Carlton coach, Mick Malthouse, claimed to have been told by the current Carlton and former Adelaide CEO, Steven Trigg, that Adelaide had illegally signed Betts 18 months prior to him departing Carlton. Adelaide categorically denied the claim, as did Carlton and Betts' manager. Betts and all other parties were subsequently cleared of any wrongdoing in the affair. Following on from this controversy, Betts improved on his stellar 2014 season by kicking 63 goals in 2015, finishing third in the Coleman Medal, and finally achieving All-Australian honours. Betts also was awarded the Goal of the Year in 2015 for the second time in his career; against Fremantle in wet conditions, he managed to control the ball near the boundary at half-forward and kicked a left-foot torpedo punt from 50 metres out on the boundary line, which dribbled through for a goal.
Betts married his long-term partner, Anna Scullie, in a surprise wedding in August 2015, after several years' engagement. They have four children: Lewis (born in October 2012), Billy (born in March 2015) and twin daughters (born in April 2018).