The Loss of Methot was unavoidable, as Most teams "lost" players for nothing, and some gave the VGK something to not select a player they did not want to lose, but could not protect.
Dorion did not want to lose Methot, but he also could not protect Methot, mainly because he was forced to protect Phaneuf.
To Dorion's credit, it was reported that he did try to get Methot back from the VGK, but their price was too high.
He could have protected Methot by going 4 and 4, by exposing or trading Ceci, so yes, there were options. The 4 and 4 route would have meant exposing one of Brassard or Pageau, so it's a question of who is more valuable to the team. There's also the option that many other teams took; pass along picks to get LV to select someone else.
Methot ended up getting traded for a 2nd round pick and a warm body prospect, so the idea that the price was too high to re-acquire him seems to hinge on the premise that Vegas was asking more from Ottawa than it would accept from others. There's no evidence to suggest that is the case. It's possible that LV overestimated his value when negotiating a protection scheme with us to have them select someone else though.
The simplest explanation is that Dorion felt that he could do more with the salary/cap that losing Methot opened up than he could by retaining Methot when considering what he would have given up to protect Methot. From the outside, this situation has very much the look of a budget influenced move, which is fine but you got to own it for what it was, not claim there were no other options.