It should like the actual misbehaviour was that coinbase was running multiple trading algorithms, one to hedge and one to arbitrate between exchanges, and they sometimes incidentally traded against each other.

Running multiple algorithms is as common as writing multiple unit tests. That is standard operating practice.

What is also a common practice is adding a netting layer so that your algorithms internally settle before sending out trades to the market. This is generally done to save trading fees, but it didn't apply to Coinbase because they are also the exchange.

So, overall it sounds like inexperience, not malice.