[Dutch Alex]

Yep correct!
Unless there was obviously OBS to prevent to make an double. Then the runner clossed at home (in this case the runer on 1st) has ALSO to be called out...

I've also never seen this play before. Must be an mad-house on the field. People screaming, coaches who know nothing but complaining anyway, etc, etc. And in the end you're the bad guy! In my book you've done it right.