dl324:
The resistor on the lead marked Dout wouldn't be necessary and a resistor from gate to source would have been included so the gate wouldn't float when the GPIO port wasn't active.
This is all based on assumptions, which is why it can be a time-wasting exercise if there's inadequate details to begin with.
Additionally, if you assume a BJT, then the input could become floating under those conditions you mentioned too maybe, right?
Also ----- using series resistor for gates of mosfets is not uncommon.
It may well be a BJT. And all I'm saying is - if there's not enough information to start with - then it's like a goose chase.