Gotta do what ya gotta do. But freaking out is likely the last option I'd chose, especially after a holiday weekend where nobody has been around.
If you really think it's powdery mildew, fill-out the troubleshooting form, and include some fresh pix. Search onsite for pix of actual powdery mildew, and compare to yours.
Google "cystolith hairs", and do some research.
Many plants have trichomes of some sort or another.
Trichomes - Wiki
A very useful (off site) article about cannabis trichomes:
Trichomes and You