Scottie tells Madeleine that, having saved her once, he's committed to looking after her forever. This makes his feeling of guilt after her death that much worse. Here Hitch's screenwriters are hinting with foreshadowing at that later, all-consuming guilt.
CORONER: Mr. Ferguson, being an ex-detective, would have seemed the proper choice for the role of watchdog and protector. As you have learned, it was an unfortunate choice.
This is one of several snide remarks that the coroner makes in Scottie's presence at the inquest. Several times during his speech, the official goes out of his way to make Scottie feel guilty, editorializing about Elster's choice of an acrophobic ex-officer to protect Madeleine. We'll find out later just what was motivating this choice; far from being "unfortunate" for Elster, it was exactly what he was banking on: that Scottie would be unable to come to Madeleine's rescue, as the judge puts it, "when he was most needed."
CORONER: Nor does his strange behavior after he saw the body fall have any bearing on your verdict. He did not remain at the scene of the death. He ran away. He claims he suffered a mental blackout and knew nothing more until he found himself back in his own apartment in San Francisco several hours later. You may accept that or not. Or, you may believe that, having once again allowed someone to die, he could not face the tragic result of his own weakness, and ran away. That has nothing to do with your verdict.
Ouch. With his references to Scottie's "conscience," the coroner fans the flames of Scottie's guilt. Officially, he's exonerated from responsibility, but the coroner obviously thinks he's acted shamefully.
ELSTER: There was no way for them to understand. But you and I both know who killed Madeleine.
Elster's reference to Carlotta is meant to displace Scottie's guilt. It's no help. Elster's the guiltiest one in the bunch, but he seems completely untroubled. Diagnosis: sociopath.
PSYCHIATRIST: He is suffering from acute melancholia, together with a guilt complex.
There you have it from the expert: the "guilt complex" is Scottie's official diagnosis. Guilt, coupled with the loss of his love, has undone him.