For sure. It's easy to make that mistake, especially if you're in a hurry.I've ridden transit all over the world, I use GO all the time and ride TTC/MiWay/Zoom and it still happened to me the first time i rode UP Express. They installed two readers on the same platform that looked identical to each other. They are the same size and shape, same tap face and they were pretty much painted to same colour (one was light purple/greyish vs light green'ish). I tapped the GO reader at Bloor station and tapped UPX at Pearson and was charged max fare. It took several calls to sort it out because if you phone UP Express lines, they can't actually do the refund, it's done through GO Transit, so you get transferred over and have to start the process again.