Kovalchuk's retirement was in the offing before that, it's just that that is when he formally retired. The news about Barroway was announced on June 29th. Remember that he loaned money to the Devils so that they could make payroll - Vanderbeek was not going to last much longer as team owner either way, either the league would take over the franchise or it would be sold.
Reports around that time had linked Barroway as the new owner, of course ultimately he was not. I find it hard to believe that the guy who didn't own the team, was able to authorize Lou to spend to the cap.
This obnoxious link shows that there are zero mentions of Harris as a potential owner for the Devils before July 11th. Sure there is stuff we don't see behind the scenes but that is all heresay and speculation. Sticking to just what we actually observe, the Devils have been fiscally competitive for the last dozen + years.
The Devils were still owned by Vanderbeek during the compliance buyout period last year. They spent the money on Ruutu and Brunner after ownership was decided, and I believe they signed Zidlicky and Jagr after it became clear there were interested buyers.
Brunner Sep 24th
The sale was formally announced on August 15, 2013
I see you left yourself some hedge room with "after it became clear..." but it's nonsense. We signed 4 players, 3 of them to medium + sized contracts in the opening days of free agency (which started july 5th that year for those who may have forgotten)
And while I am too lazy to actually double check this, as of July 11th we are probably already over the cap, it's not until Kovy retires that we actually can spend any more, which is where the money to sign Jagr and Brunner comes from, not new ownership.
2009 - 10th in average cap hit
2008 - 2nd in average cap hit
*2013 was a weird year for a lot of teams in terms of spending, undoubtedly due to the lockout, cap adjustment, compliance buyouts etc. We finished 17th in cap spending that year, and a lot of other teams that no one in their right mind would say is "fiscally questionable" spent the same as NJ.