Hmmm.... 22 feet... and yet clearly a higher drop allows for an opening up and dispersion of water dropped over a fire. The idea on the drop is to drop water over a wider area than to simply have the bulk drop of the water in a tightly concentrated area.
As you can see in these videos.
https://www.politicaljack.com/threads/trump-tweeted-condolences-to-france-regarding-their-horrific-fire-today.120536/#post-2395254
What does this example of yours have to do with anything? The fire retardant fell on a tree and the tree fell on the firefighter. What are the physical characteristics of retardant that may make it behave differently than water?
The dropping of water from these planes is height dependent. A high drop disperses the water.