From the point of view of Appians investors in their fund ,they...

From the point of view of Appians investors in their fund ,they have all lost a bunch of money as a direct result of the Harte investment .So I would suspect that the principles in Appian would be subject to legal action from their investors .So one motivation is to get a better offer for their investment and to protect themselves against investor lawsuits .
Appian had plenty of time to put in a bid but were greedy ,charged horrendous interest rates to Harte .Obviously they didn't have the support of Harte or the bank that held the primary debt which Silver Lake now holds .
New gold has been poorly managed for years as witnessed by the steady decline in share price ,they have just sold their jewel in the crown Blackwater development to raise cash .They have lost 25 million which they invested in Hartes shares .I would imagine this is just a negotiating tactic by Appian to reduce their losses as much as possible.
One would imagine that Silver lake is in the drivers seat with Harte management on their side ,they have funded the operation of the mine whilst this gets legally sorted out ,one would think that this wont take very long for the judge to make a decision .
Presumably Silver Lake has a good idea how much the mine is currently worth and how much they are prepared to pay at current gold prices ,
In my opinion Silver Lake is in the drivers seat .