Despite there being a pre-release picture of Lumpy holding a giant toothbrush, it never actually made it into the final cut. (the writer, Warren Graff posted a comment on sneak-peek page saying that he didn't remember the giant toothbrush in the script).
The giant toothbrush, however, can be seen in the background next to a clump of trees before Lumpy floats up to the branch with the balloons.
It might have also happened with Lammy and Mr. Pickels in A Bit of a Pickle, since the pre-release image of them also features a giant toothbrush.
This is the only time Lumpy dies from falling from a long height, in other episodes when he falls from a huge height he only gets injured.
When this episode was first uploaded, it was somehow deleted for an unknown reason.
Lumpy flying by tying a bunch of helium balloons to a lawn chair is similar to a real-life event that occurred in 1982 where a trucker named Larry Walters flew 15,000 feet by tying 45 helium balloons to a lawn chair.
Writer Kenn Navarro said on the "Burn After Reading" page (p2) that Handy was going to be in Toothy's place, but was changed to Toothy because he has hands and wanted to make it clear that he was tarring his roof. He felt it was important to see somebody pushing the broom around, something that Handy wouldn't be able to do (also seeing how Warren Graff is the voice actor for both Toothy and Handy, it wouldn't take much effort to change from Handy to Toothy).