The shelf does not tilt when Maggie removes the crucifix, so there would be no effect on the clock. [However, the shelf does tilt back when Maggie returns the crucifix to its place.]
The cuckoo clock on the shelf goes from 11:25 to 11:45 in the time it takes Maggie to dish up the ham and eggs. The clock then "jumps" ahead to 11:55 in a span of about three minutes.
Maggie is seen cracking four eggs into the skillet. However, when she serves the eggs, it's plain to see that there are only two.
However, actually looking at the eggs being served, each man gets a serving of two eggs - count the yolks.
Maggie grabs the handles of hot items such as the skillet and coffee pot with no insulation to protect her from burns.
Both Gene Barry and Darren McGavin have terrible Irish accents, which they sometimes use and sometimes don't.
Near the end, just as Ben replaces the crucifix on the shelf, the shadow of a boom mic passes over a wooden beam at the top left of the screen.
When Maggie makes ham and eggs for the two men, she says she is making scrambled eggs, but when she puts the meal in front of them, the eggs are fried.