When Jerry produces the pail of sand, he is missing his red trunks. He regains them when he sets the pail next to Tom.
When Jerry creates the face on the post, he is somehow able to create shades of white and red with a black marker.
When Jerry is walking away from Tom with the bottle cap on his head, the view changes to the crab. Just after Jerry walks into view, the crab's left 'arm' disappears for a frame or two, leaving only a disconnected claw lying in the sand.
It is never shown or explained how the inflatable yellow toy Tom is floating on gets refilled with air at the end of the cartoon.
When Tom is chewing on a piece of the banana that Jerry gave to him he makes a crunching sound as he chews it.
Since a banana is soft it should make no noise at all.