Great post, I have hear about this but have not found an article explaining it so well.
Software errors like this are a major problem for any new system, especially for blockchains. Open-sourcing is a good way to have hundreds of developers search for errors, but it also creates a false sense of security. There are still many errors found in Linux or similar software that has been open for decades.
With blockchains, it is a little bit different, because only the protocol is fixed, the implementation can be very individual. The concept of Bitcoin is, that you should not trust any developer to provide you with secure code, the blockchain is the only and absolute truth. I would like to see more implementations that do not rely on Bitcoin Core to decentralize everything a but more.