Generally I haven't been getting defects for INR cases opened if refunded (without going to ebay for decision). I think I did once, but for the rest I have not (about 4 INR cases)

Ebay also send an email after refunding stating that  "This request won't count against you when determining your seller standing", whatever that means.

A defect shouldn't be appearing for a cancelled transaction in any case, but they do dissapear after a few days. If a transaction is cancelled I should also get my fees back, not sure if fees are refunded for these INR cases when the buyer is refunded though.