Police raced to the scene in an affluent town near Glasgow after the 78-year-old was found injured in his garden.
The freak accident happened at his home at Silverwells Crescent in Bothwell, South Lanarkshire, shortly after 2pm yesterday.
A Police Scotland spokeswoman said: "There are no suspicious circumstances."
The man, named locally as the prominent lawyer Thomas Friel, remains in Hairmyres Hospital in East Kilbride.
Shocked neighbours said the street had been filled with police officers and that the road had been taped off.
Forensic science officers were also seen entering the house.