Secret Service director Kim Cheatle slammed for BAD excuse

Secret Service director Kim Cheatle was slammed for a bad excuse she made for what happened when Trump was nearly assassinated. She claimed the roof the shooter was on was too sloped to have her own snipers on. Ironically, she had snipers on another roof that was also sloped, so what exactly is her real excuse for this major oversight that lead to Trump being shot and a firefighter losing his life?