It does sound as if it has snapped completely and not just torn . So will require surgery at some point . They do tend to get on tendons reasonably quickly as they contract and are harder to work with.
They will either sew the ends together with a suture or put in a tiny metal pin with a suture attatched and sew the tendon to that .
There is such a thing as an alvusion fracture where the bone comes away with the tendon intact ( ultrasound or x-ray will spot this ) ,this is then pinned back together.
1 day in hospital , maybe 10days in a cast or splinted . Back to hospital for wound check and clean up , then maybe 4 – 6 weeks immobilised .
Then comes the physio, 1 or 2 months to get back to a good level of use .
snapped a thumb tendon twice so becoming abit of an expert, and my Mum did the same as your friend making a bed and left it and its permantly crooked