In this matter his non-pardon is as good as an indictment as far as I'm concerned. Based on stories I've read, Mexican diplomatic operatives were involved in this early on, and those agents didn't have any hope for a fair process.
the lynchpin was the testimony of other agents, from what I can tell. Nevertheless, it is so excessive a sentence as to be obscene. I think the Prez will pardon them. But he sure wasn't going to do it off the cuff and run over the prosecutor without good cause.