My experience in negotiating and mediating contractual disputes tells me that if both parties are fine with ignoring a deadline then that's what happens.

The contract actually states that Teck will lose their back-in right if they do not give notice to Copper Fox within 120 days of the delivery of the Feasibility Notice. Setting apart all the argument about the FN being delivered...if it was, I can't see Teck going offside on a contract by casually ignoring the deadline. The minute they go over that 120 days there could be a legal argument made that they lost their option. Also, once they go over the 120 days without giving any notice, they can no longer refuse the Feasibility as "bankable" because the contract says 120 days after delivery of the Feasibility Notice, not the Positive Bankable Feasibility Study. (I'm on the side of believing it was delivered properly on time.)

We may not hear anything exactly on June 4th, but I'm sure something legal and official will be happening on or before that date, even if only to extend the deadline. It was around the 60 day JV date that they all went into blackout and I don't think that was a coincidence. Both parties have to watch they don't go offside on the legal agreement no matter how chummy the negotiations are.