However when representing an reputable organization, people are expected to be cautious or otherwise required to have their comments reviewed and most organizations would enforce this to protect their brand or reputation.

As Carl Sagan said it best, extraordinary claims require extraordinary evidence. This was a pretty extraordinary claim and multiple senior staff at the org endorsed the comment without even a cursory check first. I would think serious observers are more concerned by the process and controls in OpenAI or lack thereof here, rather than a specific single mistake.

Like them or hate them, OpenAI is the leader in the industry, and everyone lookup up to them and their employees in a public forum for credible information so will hold them to higher standard than a lesser known lab.

The burden of checking for quality comes with having a reputable brand . The burden is being monetized / compensated with the valuation or size of fund raise a org is able to command.