The 29 year-old passer-by, who does not wish to be named, was struck on the shoulder and knocked to the ground, a moment dramatically captured by nearby CCTV cameras.
A Health and Safety Executive inspector said: “It is pure luck that it missed his head, otherwise he could well have been killed.
The man escaped with a cut and bruised shoulder but suffers muscle spasms as a result of the incident on Camberley High Street on last May.
Guildford Magistrates’ Court heard that Majestic Construction was cleaning stonework and installing pigeon spikes above shops when the incident happened.
A mobile elevating working platform was correctly being used for the task, but as it was being moved it struck a building and dislodged a chunk of masonry weighing 8kg that fell almost 8m to the pavement below.
An HSE investigation found that while barriers were placed around the nearside support legs of the MEWP, there was nothing to prevent anyone from walking directly underneath the ongoing work overhead.
Magistrates were told that some of the barriers were being moved to provide a safe-working cordon further along the street where the MEWP was headed, but nobody warned the pedestrian to stand back or to be aware of the overhead work.
The incident could have been prevented had the work been better managed with a proper safety cordon in place.
Majestic Construction was fined £8,000 and ordered to pay £5,473 in costs after pleading guilty to a single breach of the Work at Height Regulations 2005.
After the hearing, HSE inspector Andrew Cousins said: “This was an entirely preventable incident that resulted in a large chunk of masonry being knocked onto an entirely innocent pedestrian. It is pure luck that it missed his head, otherwise he could well have been killed.
“Simply fencing off the area beneath the works and providing an alternative route around it is all that was necessary.”