I´d like to aboard two points here.
First one. The scorpio moon and the cancer sun. When you see this combo, you can imagine a deeply emotional person; that complements itself with a fiery scorpio moon. In my experience, the scorpio moon person (apart of the pluto/scorpio aspects) tends to have a dramatic experiences. They are like a problem magnet. And offcourse talking here about a cancer man, be sure that the lost of his family members would be a deep wound in his soul. After all, who can be a cancer without a family?
Second one. Transits: As well as you maybe know, the pluto transit in capricorn is opposing all the cancer suns people. When you have this powerfull transit: the lost, (Literally
luto the god of underworld, the god of death), may appear in your life like the death incarnate in your life. When you have the pluto touching a personal planet you can go throught a really deep dark time.
Pluto is now in his fourth house, (home,family) and is oppossing his sun (ego,father). When this transit happens, you have the challenge of destroy and rebuild yourself (sun), letting go all the masks that hide your real essence, and cutting all the bounds that do not allow you grow as a person. I don´t know if the dead of his father was recently. But seeing the chart, in this case Pluto/Sun transit in the fourth house can represent literally the loss of his father.
But it is not the only relevant transit in his chart. The saturn transit in scorpio , conjunct his moon (mother) in the past years, it could represent a lost too, and maybe if it isnt, could be a pretty rough and depressing time.
Yes it is indeed a hard time, that can affect him a lot. Seeing his nature, mybe he want to maintain the pain for his own. He may need his own space. It´s indeed understable, but if you have the opportunity u should take care of his feelings and try to be a guide in his life.
Wish he gets better and Hope it helps you.