What would the benefit of an informant be to a prosecutor? He doesn't build the cases, LE does. He simply decides whether to bring charges and then proves his case in court. He couldn't suddenly file charges against a person or entity with no investigation.
Similarly, he doesn't work for the defense, so someone presenting an alternative theory of a crime would hold no interest to him (or worth to them).
Even if, and I'm totally speculating here, the cops investigating a certain case were corrupt, Gricar wouldn't be much of a help. He's not going to hold some outsize sway within LE.
And certainly destroying his means of logging evidence and staging a relaxing/romantic vacation don't really jive with meeting an informant.