AITA for kicking out a potential big donor at the animal shelter because of how he handled the dogs?

I’m 28F and volunteer at a small no kill shelter. We run on donations, and money’s always tight vet bills alone are brutal. Last weekend a guy (mid 40s) came in saying he wanted to adopt a dog and that his family might donate a decent amount if things went well. While showing him around, he started being way too rough: yanking leashes hard, grabbing dogs by the scruff to test them, poking a puppy in the stomach to make it yelp. I tried gently correcting him (these guys have trauma, let’s go easy), but he said he grew up on a farm and knows what he’s doing. It got bad when he tried to pick up our skittish shepherd mix (abuse survivor) without warning she whimpered and backed away. I stepped in, took her back, and told him if he couldn’t be gentle with the animals he had to leave. He got pissed, said I was throwing away a big donation opportunity, called me overly sensitive, and left. The shelter coordinator later said I should’ve let her handle it or given him more leeway because we really need the funds. A couple other volunteers agreed it was shortsighted. My boyfriend says I was right to protect the dogs, but now I’m wondering if I cost the shelter something big over one bad interaction.