Rule of Law not working as worded

Gun Bunny

The Rule of Law enchantment support reads that players may only play one card per turn. I was in a match and the AI cast two vanguard supports on the same turn, but when I cast Brought Back, my first creature returned as normal, then Rule of Law activated and I didn't get the second creature from my graveyard, despite Brought Back specifically putting the two cards it grabs directly into play.

Magic:PQ Support Team

Hello @Gun Bunny

Do you remember what Supports were in your graveyard when you casted Brought Back? 
Brought Back also targets none Vanguard Supports in the graveyard, so it is possible that you had another Support in your graveyard that was returned to the battlefield instead of your second Vanguard.
Waiting for your response and thank you for the feedback.

Gun Bunny

It should have pulled two creatures, which were in the graveyard, but instead pulled only one before the activation showed on the battle log.

My opponent was the one casting two vanguard's in the same turn, not me.