It's your technique. For a M1, pick up the bar between stitches, grab it from front to back, then knit into the back loop to twist the stitch, thereby avoiding a hole. If you do not twist the stitch, it's technically a yarn over.
Which, by the way, is good to know if you are knitting a pattern with yarn overs. If you forget a yarn over on the previous row, pick up that bar and do not twist it to add the yarn over without having to rip out or unknit.