Check the black plunger like thingy in the reservoir, sometimes it flips inside out, and take up space in the reservoir...
Yeah, it is possible the diaphragm (black plunger like thingy) extended itself. The weep holes allow venting and are separated from the diaphragm, allowing the diaphragm to drop down as the fluid level drops, preventing moisture laden air from contacting the brake fluid. No fluid should come out of the holes.
