After Handyman Negri install's Daniel's punch-clock, it falls as Daniel moves by it. Clearly attached with a weak adhesive, Handyman Negri reinstalls it only to have it fall again as he is walking away. A similar difficulty is found in securing Grandpere's clock not just because Grandpere keeps punching it, but because of the clearly weak adhesive used to hang the clock.
When Mr. Rogers unzips his sweater to begin singing "Tomorrow", a loud boom and scratching sounds can be heard over the soundtrack, indicating that he bumped his microphone.