It isn't theirs to sell at discount prices!
Competition is not the undercutting of market rates, it is the process that determines the market rate. Why would you sell a commodity for less the market will bear? That is denying money to investors, who would certainly expect the circumstances to be investigated, with a view to answering that question. I am sure that the investigations would centre on what the individuals concerned might gain (bribes? influence? help friends, inexpectation of return benefits?). If any connection at all could be shown between the directors selling crude at artificially-low prices and those buying it - and it seems unlikely that there would be none - then it seems that some gain would be strongly suggested. Since that is at the expense of the investors, that would I assume be seen to constitute fraud.
The people deciding the price of the oil don't own it. Selling something you buy is not an analogy. You own that, unlike those deciding the price to charge for their company's oil. They are acting on behalf of their shareholders, who between them own the company and thereby all its assets, including unsold product. If the price is low, then those shareholders are being served badly, and the directors can be held legally responsible. If it is possibly they made material gain by serving their shareholders badly then they would face criminal charges!