They always pay!!! Most pet owners get insurance after their pets have been sick or injured believing that next time they will be covered. NOOOTTTTT.
My dog was hit by a car and I spent $2K on vet bills. I got insurance and a few months later his hip was showing problems. Cirgury and therapy were over $3K and VPI would not cover because it was "pre-existing".
My sister's puppy swalloed a rock and it cost almost $2K to remove it. She got a check on the mail in less than a week for 90% of the cost. Lesson learned. I'm getting Trupanion for my next puppy.