Mechanic put breaks on my car hydraulic fluid in rear leaked bad out of nowhere

Hi, this is Bo, an auto expert on RepairPal's Car Genius team! Yikes, sounds like your husband's friend might have accidentally messed up something important. On your 2001 Mercedes-Benz S55 AMG, the BAS and ESP lights coming on, combined with a hydraulic fluid leak, could be related to the braking system or even the air suspension. If it's leaking from the rear driver's side, it might be a busted hydraulic line or connection. Since these systems are critical for safety, I'd recommend getting it to a professional ASAP to avoid any dangerous driving conditions. If you need any further advice or want help finding a trusted RepairPal shop in your area, please feel free to call us at 877-913-1554!