I had a couple of interactions like this while in Italy recently. I’d not even opened my mouth and the person responds in English. I specifically selected clothes that don’t have any text on them, but I strongly suspect it’s because I’m white as fuck and look as Midwestern American as one can.

I didn’t have any trouble though, most of the Italians I spoke with seemed happy that I’ve been trying to learn their language and were happy to talk in a mix of Italian and English to meet me where my Italian level was. It was interesting comparing how in the touristy areas of Italy many folks spoke such perfect English they’d lost most accent (or perhaps were themselves transplants) but once I got out of the touristy areas folks were willing to work with my limited Italian