Oh no.
Check the undersides of the leaves, the spots could be from them biting it.
If so go to home depot and say something like, "My friend asked me to get a spray for spider mites, he has them in his vegetable garden, can you help me?"
That way you don't really have to talk about legitimate gardening, and you get what you need
edit: The above pictures are 'spider mites' they usually come and feast on unhealthy dry plants.
I hear the best way to keep from getting mites is keeping your plants happy, and by misting with water.
But misting with water can bring about rot or mold if your grow area isn't well ventilated. Also, in the flowering cycle you don't want to mist because resin is produced to keep the buds from drying out.
Best of luck