There's more accumulated gunk on hotel irons than you could imagine. Many of them are much hotter than what people are use to at home (or many people using them don't iron their stuff at home) so they are constantly melting synthetic fibers and messing up the iron for the next person. Ever see somebody in a rayon or poly shirt that has the "iron shine" marks? What caused the shine is stuck to their iron someplace, waiting to mess up somebody's stuff.

I would chalk it up to experience and leave it at that. Going forward, try to iron your stuff inside out so that should it happen at least it will be on the inside, and get into the habit of ironing stuff when using a strange iron through something like the Protective Ironing Pressing SET at $12 for two on Amazon, or my method, just a piece of a plain white COTTON (not synthetic) old Tee Shirt and iron through that.