How would you handle this?

Tonight I had a few friends over for a bbq, my best friend (female) was in the bathroom. She came out, and went outside. Then my husband went into the bathroom. A few minutes later, he comes out of the bathroom and tells me that her period blood was all over and under the seat. He scrubbed it with lysol wipes but it still skeeved him out. Can't really blame him. We wound up changing the toilet seat.

Would you mention it to her? And how?