A nervous cat does not necessarily equate with a vicious or aggressive cat. Far from it, I have known cats to piss in fear but not attempt to inflict any sort of injury.
Furthermore it is perfectly normal for a cat to run and hide in fear upon the arrival of a strange human into their home, even a cat which isn’t necessarily scared of humans on neutral territory such as a street pavement. Strangers in the wrong setting is a perfectly reasonable thing to be wary of.
In the case of your friends cat Dicky I would initially attempt to play it softly softly – sit quietly for a few minutes in the same room as the cat talking softly and reassuringly to it in an attempt to entice it out of its hiding place. If it appears just continue to sit talking reassuringly and reaching out a hand that it can sniff which doesn’t appear threatening. If it comes in touching distance don’t initially attempt to pick it up but stroke it gently to reassure it. When you have won its confidence and it no longer sees you as a threat gently pick it up whilst still talking reassuringly to it.
The whole process might take far less time than you might imagine, possibly minutes, cats can be very quick at judging someone.
If you do struggle, and you are not intending to offer the cat a home yourself anyway, I would very strongly suggest that you contact Cat Protection, they will come and collect the cat themselves and re-home it. No one is more experienced in such matters than Cat Protection.
Really sorry to hear the sad news concerning your very old friend btw.