The Hedera Hashgraph codebase will be governed by the Hedera Governing Council, and will be released for public review with Version 1.0, expected in 2020. The codebase will be open review, meaning that anyone will be able to read the source code, recompile it, and verify that it is correct. In this way, the Council will not be change the codebase without everyone seeing those changes, which ensures transparency.
The nodes that the Council members run will have no special role in consensus - their influence, like all others, will be weighted only by their stake of hbars.
In addition, the Hedera network is fair because there is no leader or miner given special permissions for determining the consensus timestamp assigned to a transaction. Instead, the consensus timestamps for transactions are calculated via a voting process in which the nodes collectively and democratically establish the consensus. The network is fundamentally fair because no individual can stop a transaction from entering the system, or even delay it very much. If one (or a few) malicious nodes attempt to prevent a given transaction from being delivered to the rest of the nodes, and so be added into consensus, then the random nature of the hashgraph gossip protocol will ensure that the transaction flows around that blockage.