Yes, we didn't realize right away that we were out of RC because steemd.com wasn't yet reporting correct RC values (it was reporting we still had about 40% available) and because some non-top 20 witnesses were still letting transactions through without verifying RC. The RC system doesn't require consensus, so if a producing node puts a transaction into the blockchain, the other nodes will accept the transaction even if their own internal calculations show that the transactor didn't have enough RC.