It doesn't happen often, GF, but as with all wild animals, they will defend themselves and their young. This time of year there are kits out and I suspect the coons were defending young ones. Raccoons can be large--30 pounds or better--so they can be formidable when they feel threatened.
"We are--each of us--dying; it's how we live in the meantime that makes the difference."
"It's not what you gather, but what you scatter that tells what kind of life you have lived!"
"Be kinder than necessary, for everyone you meet is fighting some kind of battle."