The pilots themselves aren't likely to contact the wilderness agency directly. That's the responsibilty of the company management, my man
As DD stated, it's not the pilots responsibility to report their actions to the USFS. The Company has a USFS rep that may have dropped the ball.
Brown said he wasn't informed about the drop until a month after it occurred.
The pilots didn't even report it to the management:
The incident went unreported until wilderness rangers from the Inyo National Forest began fielding questions from hikers and climbers about the large, red stain across an otherwise white granite mountaintop.