Alarmist article by an alarmist commander. Completely unhelpful, if not stupid, thing to say.
Regardless, Argentina does not have the capacity for a conventional invasion nor the political will for another conflict.
Military blockade by Argentinian forces, for example against fishing vessels and oil installations (when they are built), is more possible but just as less as likely.
A more practical route for Argentina would be to invest in the Falklands over a long period of time, to show the benefits of Argentinian influence. This is self-defeating for Argentina, as it could be construed as recognising British sovereignty (COULD, by some), and because of 1982 and the recent sabre-rattling by President Fernandez, the islanders have little reason to trust such efforts, and would view such overtures in a negative light (in fact, they do) and therefore Argentinian investment efforts would be turned away by the Falkland Islands government.
Furthermore, about the UK "stealing" the mineral resources and profitting from them: has anyone on this forum made or willing to make calaculations as to how much the UK itself would really benefit from Falklands oil? In the same way that only the Falkland Islanders have benefitted from fisheries (the UK does not take money from the Falklands like that, per se), the oil money would probably be rolled back into the Falklands themselves.
Would Argentina, if it had sovereignty over the FI, let the oil money stay with the islands, or take from them?