Jim's not very good with math. A 4.6million dman on the Oilers at the start of the season would not have fit under the cap without using Kane's LTIR, and the Oilers could not be cap compliant to activate Kane off LTIR in that scenario. They can add that money at the deadline only because of how cap is accrued. This also ignores the fact that the Oilers can actually add a cap hit double or quadruple that at the deadline when retention is factored in.
The Oilers management miscalculated thinking they could get these RFAs for cheap as most teams usually do, but there is no scenario where Broberg could have been matched in a world where Kane returns from LTIR during the season (which seems inevitable given current reports that he should be back by Jan/Feb). The only way they could have made that work is if they traded 4 million off their cap and currently there isn't a single 4 million dollar player on the team who doesn't have a NMC except for Arvidsson who they just signed, and Ekholm who they obviously can't afford to trade.