... for the legally recognized government of France, in support of the Allied war effort ...
No he was not, we are talking about an event (Bad Reichenhall) which took place in May, 1945, and Petain was then a thing of the past. Leclerc and his men were acting under the orders of the GPRF which had been created the year before.
For more info, see below:
The Provisional Government of the French Republic (gouvernement provisoire de la RÃ©publique franÃ§aise or GPRF) was an interim government which governed France from 1944 to 1946, following the fall of Vichy France and prior to the Fourth French Republic.
Following the Battle of France in 1940 the state of Vichy France had been established under the rule of Philippe PÃ©tain. However, after Operation Overlord, the liberation of Paris and the fall of the Chambois pocket, the Vichy regime dissolved. Jurisdiction was then seized by the Provisional Government under the leadership of Charles de Gaulle in the wake of the Allied front lines moving through France.