I've been to a few interviews with startups. Some of them didn't care about not having their language on the résumé while some of them did. The impression I got is, you can just tell which one of them are looking for a code monkey and which ones want you to take a bigger role of contributing as a software engineer.
If you ended up in that situation, obviously pick the candidate more familiar with your stack, but that's a hypothetical, hiring in this business is not generally characterised by a glut of qualified candidates.
