From my readings it was the British and Canadians who called them Ronsons. It is at least a common story from many many otherwise reliable accounts such as
Brigadier William Denis Whitaker who commanded the 1st Battalion,
The Royal Hamilton Light Infantry (Wentworth Regiment) who wrote
Normandy: The Real Story of How Ordinary Allied Soldiers Defeated Hitler, Victory at Falaise: The Soldier's Story,
Tug of War: The Allied Victory That Opened Antwerp,
Rhineland: The Battle to End the War , and
The Battle of the Scheldt and was a local hero.
His
Victory at Falaise told the desperate story of the 12th SS Panzer Division
Hitlerjugend and II Canadian Corps.
Ken Tout, who served as a tank gunner and tank commander in the 1st Northamptonshire Yeomanry in Normandy, and wrote
A Fine Night for Tanks: The Road to Falaise also recounts the Ronson account