In the image below it appears someone has sold at least one Plex at 910 ISK when i very much suspect they meant to sell at 910,000,000 ISK. A classic miss-posting that can occur in Eve.
The current view is that the sandbox nature of Eve Online means that players must live with those mistakes - CCP are not here to protect players from themselves.
In the above case, this could be a Plex trader - in which case that is less of an issue. They can take such losses and likely make such a mistake every so often.
It could though be someone who has spent $15 to buy a Plex and miss-sold it on the market - that would be a bigger problem. i would hope they get their due ISK if they put in a ticket to CCP.
However, it does point to the flaw in the current market system. On today's exchanges - Sell orders that are priced below posted below Buy orders are settled at the price of those Buy orders.
So, in the above example, the Sell order would have sold at something like 868,000,000 ISK even if it was posted at a mere 910 ISK.
I am no coder - but i wonder how much additional time and resource this would require?