I disagree. You appeal the judge's "decision" which was to ignore your motion and grant the other party's motion.First thought would have been an appeal, but since the court did not deny my motion, there's nothing to appeal at this point, is there?
I see a couple of issues that might work against you.
According to LRS C.C.P Art 561A(4)
"A motion to set aside a dismissal may be made only within thirty days of the date of the sheriff's service of the order of dismissal."
No. Even if your motion had been granted, the plaintiff would have found out about the motion anyway and would have had 30 days to file a motion to set aside the dismissal. If the motion to set aside the dismissal had been denied then they could have appealed the denial.Their only option would be to appeal after dismissal
https://legis.la.gov/Legis/Law.aspx?d=112183
According to the Supreme Court of Louisiana:
Quoted from:“an ex parte dismissal may be rescinded by rule to vacate it upon a showing that a cause outside the record prevented accrual of the five years required for abandonment.” DeClouet v. Kansas City Southern Railway Co., 176 So. 2d 471, 476 (La. App. 3rd Cir. 1965). Only two categories of causes outside the record are permitted; namely, those causes falling within the two jurisprudential exceptions to the abandonment rule. Those two exceptions are: (1) a plaintiff-oriented exception, based on contra non valentem, that applies when failure to prosecute is caused by circumstances beyond the plaintiff’s control; and (2) a defense-oriented exception, based on acknowledgment, that applies when the defendant waives his right to assert abandonment by taking actions inconsistent with an intent to treat the case as abandoned.
http://www.lasc.org/opinions/2001/00cc3010.opn.pdf
(The 5 years mentioned in the case citation has apparently been changed to 3 years by statute.)
Another thing is that judges disfavor dismissals when a case can be adjudicated on its own merits.
I'm guessing that your next step might be to file a motion for reconsideration on the grounds that exception 1 has not happened and the judge erred in granting the motion for the substitution of plaintiff.
That cannot be ex parte so you would have to serve the motion on the plaintiff who would have the opportunity to respond with an explanation of why exception 1 applies.
It's anybody's guess as to how the judge will rule on that.
But if he rules against you I hope you are prepared to raise a defense based on not owing the money rather that some technicality that you manage to come up with.

