I really don't have a sense of the strength of the case because I don't know the evidence (and media reports of legal matters seem to me to be more often wrong or at least misleading as they are correct), but note that prosecutors typically don't bring a case they know is weak because of their own concerns about being potentially embarrassed. It is probably a safe presumption that in the minds of the prosecutors they have decided they have a better than 50% chance of winning if there is not a plea bargain and the matter goes to trial, and thus an equally safe presumption that prosecutors have evidence not yet made public that they believe supports a conviction (and also, by implication, overcoming a consent defense).
FWIW, unless it is a case that I am involved in where I am required to use my professional judgment to assess odds and probabilities of success or failure, with somebody else's cases I have found it best to just grab the beer and popcorn and not even attempt to draw any conclusions but to simply observe it and watch how it all plays out. We can't do anything about it anyway so why go through the angst of speculating?