is it ok to run the air with the engine off?

What is your question?

i was running the air in my car with the engine off for like 15 minutes cuz i was just sitting in a parking lot waiting for someone - the next day my car wont start and my mechanic said that running the air without the engine on had drained the entire battery out and the entire electronics needed to be reprogrammed - ive run the air like this a million times in my car and never had that problem - seems like bs to me - can anyone confirm?