On account of a thread, where some guy's friend (in another thread) added coolant to the brake fluid reservoir, I took the precaution to clearly label mine, so some "fool" wouldn't likely put in the wrong fluid.
That thread you were reading, that event never happened. That guy confused what his friend did to his car, there was no mix up of fluids.
Take it to a certified mechanic who works on hybrids not your friend who is a handyman or the neighborhood mechanic