Bill Cosby has lost his first battle on the issue of whether an alleged 2005 agreement with a prosecutor bars his current Pennsylvania prosecution. The judge ruled at the end of the hearing, denying Cosby's motion to dismiss. To date, the judge hasn't explained the basis for his ruling. If he ever does, his stated reasons for denying Cosby's motion could significantly affect any chance Cosby has of succeeding with this issue on appeal (an issue that will only come up, of course, if Cosby is convicted).
First, some background regarding the information and materials the appellate court will have before it when making its decision. An appellate court doesn't take any new evidence. Instead, it makes any evidentiary assessments based solely on the "record" of the trial court proceeding--the transcripts of any hearings, along with any exhibits submitted to the court.
Because this is all the appellate judges have to work with, the trial-level lawyer has a critical role to play in laying the groundwork for an appeal. You'll often see trial lawyers going on and on before judges who have obviously decided to rule against them, and this is why; the trial lawyers are basically talking to the appellate court. (In one case of mine the judge literally left the bench while I was "making my record"; all I could do was note that fact for the record and keep going.) So if Cosby's case gets appealed, the appellate court's determinations will be based on the evidence presented at the recent hearing.
Then there's the issue of what exactly the appellate court will be deciding--and this is where the trial judge's reasons for his ruling could become important. When a judge rules on a motion like Cosby's, he has two distinct tasks. One is making factual determinations--if the parties dispute what actually happened, the judge has to make that decision. The other is answering legal questions--that is, once he's decided what happened, he has to decide what legal result follows from those facts.
Much of the discussion of Cosby's case has focused on the legal questions--that is, assuming there was some oral agreement between the prosecutor and the defense, was it binding, and does it support dismissal? But there was a critical factual question as well. The parties had very different views of what had happened back in 2005. Cosby's team argued that there was a quid pro quo agreement, in which the prosecutor agreed not to bring charges if Cosby agreed to answer deposition questions instead of invoking his Fifth Amendment privilege. The prosecutor himself disagreed with this, testifying that he had indeed announced his decision not to prosecute, and that he realized this would lead to Cosby giving deposition testimony, but that no deal was made.
In my opinion, the factual question--which side's characterization was correct--was critical. If Cosby's team was correct and there was an actual "deal," that at least raises serious issues about whether that deal was enforceable. Conversely, if the prosecutor's description was accurate, Cosby's argument falls flat. If all that happened was a nonprosecution announcement, that announcement would be non-binding and subject to change at any time. Cosby would not have had a legal right to rely on that announcement in deciding to testify in the deposition, and if he did so rely, he shouldn't have.
This is why the reason for the judge's denial of the motion could be critical. If the judge concluded that there was no actual agreement, that's a factual determination that's virtually impossible to get reversed on appeal. Appellate courts defer heavily to trial courts' factual determinations, as long as there's some evidence in the record to support those determinations. When trial judges decide between competing factual accounts, appellate courts virtually always uphold those decisions, noting among other things that trial judges have the benefit of hearing testimony "live" instead of reading it off of transcripts.
By contrast, if the judge concluded that the alleged agreement did in fact happen the way Cosby's lawyers claimed it did, but ruled that such an agreement was unenforceable, that would be a legal determination. Appellate courts generally review legal determinations "de novo," meaning that they give no deference at all to trial courts' initial determinations. This is why lawyers trying to get cases reversed do their best to frame their issues as legal questions, not factual ones.
Again, so far the judge hasn't given the reasons for his decision, and that's not uncommon. If he continues to state his denial in general terms, and the case goes up on appeal, the appellate court will have to decide what to do with the underlying factual question. It could "remand" (return) the case to the trial judge for an initial finding on that factual issue. Alternatively, it could assume that the trial judge decided the factual question in a manner consistent with his ultimate decision. It could also decide that the factual question doesn't matter, because even if the agreement happened the way Cosby's team said it did, the appellate court would still consider such an agreement unenforceable as a legal matter. Regardless, Cosby's legal team has at least laid the groundwork for an appeal on this issue.