I say real also.
I was about that far away once (inside a building, thankfully) when an even bigger flash hit a transformer at our apartment complex. (That one set off car alarms too.
Lightning that close does sound just like that. In fact you will have already reacted to the crash of the thunder before you actually notice the flash.
This guy was a more blasť about it than I would have been. I don't think I would have been standing outside with a camera talking about it while it was still thundering.