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 blasé 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.