The late musician died instantly when a 600kg bale rolled down a steep field and crushed his vehicle back in September 2010.
Framer Brian Burden and agricultural contractor Russell Williams deny two health and safety charges, but are in court over the way they carried out their work, prosecutor Rupert Lowe told Plymouth Crown Court.
"They are both decent, hard-working men who you would never expect to be in a court like this," Lowe said, reports BBC News.
After describing how the cylindrical bale rolled down a steep hill onto the A381 on September 3, 2010, Lowe showed them footage of how a baler works and the field in which the incident took place.
"You can just see how steep it is going down to that main road," Lowe explained.
"Russell Williams told investigators he put the offending bale somewhere halfway down the field, that is the bale that landed on the unfortunate Mike Edwards.
"Once a bale rolls down a hill there is nothing to stop it. It is a risk you cannot afford to take."
The trial continues.
Edwards was cellist for ELO between 1972 and 1975. Watch the video for ELO's 'Showdown' below: