After Thomas kills the Italian in the kitchen, his white shirt is covered in blood. The black vest he wears on top of the shirt is however entirely clean, even though in the previous shot you can clearly see blood splashing onto the vest.
The red right hand that appears on the chef's shirt is upside down. Unless he never does laundry, one must presume the blood comes from the killing he is presently in the middle of. No one else is present. For him to wipe blood onto his own shirt, the thumb would be on top of the hand, not on the bottom, as it is here.
Tommy tells Charlie to put out treats for Santa and Rudolph, but the character of Rudolph as Santa's ninth reindeer was not created until 1939 by the Montgomery Ward department store which is fourteen years after the events in this episode.
At Christmastime, Tommy tells his son, Charlie, to leave a carrot out for Rudolph. The episode is set in 1925, but the character of Rudolph the red-nosed reindeer wasn't created until 1939.