What's the worst can happen by taking an appeal too early? I am asked this often, and the California Supreme Court case of Kurwa v. Kislinger (2017) 4 Cal.5th 109 always comes to mind. The worst that can happen? Five years of litigation, four trips to the Court of Appeal, two trips to the Supreme Court, and easily six figures in fees, just to get back to where you were when you first asked that question.
The nub of the problem in Kurwa was that plaintiff had two obstacles to appealability. Plaintiff used a too-clever-by-half ploy to get around one (stipulating to waiver of his remaining claim without prejudice, and a tolling agreement to boot). After realizing on appeal this could not create jurisdiction, plaintiff dismissed the rest of his claims with prejudice.
But there was a second obstacle: defendant's cross-claim was still pending. And because the trial court refused to dismiss the judgment based on the ill-conceived stipulation, plaintiff was stuck "in a legal cul de sac."