Reversed clothing
At time index 01:24:27 before he talks to his horse, D' Artagnan is wearing his blue musketeer tunic. After he talks to his horse, he turns around and is wearing black clothing. He then heads over to talk to his fellow musketeer. After he finishes talking to the musketeer, the same man hands him his blue tunic to wear. Note: D' Artagnan threw the same tunic on the ground earlier in the movie, and did not return for it.