Michael Arthur Warren died of head injuries on 5 October 2012. An inquest in Berkshire heard that just two days beforehand, two highways officers from Bracknell Forest Borough Council had carried out a 30mph drive-by inspection of the route and not flagged up any problems with the tree.
Jeremy Barrell was the tree expert appointed by the Berkshire Coroner for the inquest, held at Windsor Guildhall on 8-10 July.
Berkshire senior coroner Peter J Bedford issued a narrative verdict and a Prevention of Future Deaths Report will be issued relating to the tree inspection regime that the council had in place at the time of the accident.
Barrell said: "I suspect that this will be a matter of national interest, and especially to all highway authorities because they are charged with the responsibility of checking roadside trees."
The coroner's verdict stated that 30mph drive-by inspections noted concerns about trees, which were then reported to a tree officer.
The coroner said: "Highway inspectors received limited training in how to recognise tree problems. They relied on identifying obvious signs of decay such as a lack of foliage and dangerous leaning or fallen tree sections."
After the accident, inspection of the oak tree revealed "advanced internal decay that would not have been obvious during a routine visual inspection; a large historic occluded wound near the base of the branch that fell that would have been potentially obvious even from a drive-by inspection; a large and severely unbalanced tree branch positioned above the carriageway of a busy road; and trees surrounding the relevant oak in the same woodland strip that required pruning/felling because of their poor condition and which had not been identified by previous highway inspections".
The coroner added: "The combination of visual signs was sufficient to have caused the landowner, his agent or a highway inspector to request a more detailed inspection of the oak tree by qualified tree officers.
"Such an inspection, on the balance of probabilities, would have identified the unbalanced nature of the branch and the large occluded wound, which in turn would have led to a more detailed examination.
"This, in turn, would have resulted in intervention works to the oak tree significantly reducing the risk of the branch falling as it did on 5 October 2012."
Bracknell Forest Borough Council director of environment, culture and communities Vincent Paliczka said: "The council greatly regrets the accidental death of Mr Warren and our thoughts remain with his family.
"We adhere to industry codes of practice for inspection of the highway and will carefully review the coroner's report to determine whether any changes in our current practices are warranted."