This could be the result of a cascade of false errors all stemming from one poor design with the usb stick itself. For example, the filesystem driver will remount as readonly if the underlying driver, such as the mass storage device driver, reports a severe enough error while reading/writing. That device driver may report an error because it may be forwarding an error code received from yet a lower level driver, such as the usb controller, or it could be an error code received from the firmware in the usb stick. In my experience, the root problem is either an actual flash wear issue or a timing glitch. For example, Linux can be too fast / efficient at the bus level and expose timing bugs in cheap peripheral firmware, whereas the windows driver may have embedded longer timeouts between I/O transactions sufficient enough to avoid/bury the bug.