Born in Vielsalm on 24 December 1952, Misson moved to Liège after studying law.[2] Interested in European law, he often took up cases that challenged the legal framework of the European Union.[3] He gained notoriety from the Bosman ruling in 1995, a case which transformed the world of European football.[4][5] The ruling banned restrictions on foreign EU players within national leagues and allowed for the quick transfer of players between member states within the transfer fee requirement.[6] His other cases included trade union laws, students' rights, and the rights of residents living near airports.[1] He notably represented the labor union Syndicat autonome des conducteurs de train against the National Railway Company of Belgium.[3]
Misson died on 7 August 2025, at the age of 72.[7]