But the man's defence has argued that the Crown failed to prove he and his co-accused agreed to anything other than a ''smash and grab''.

The 34-year-old Canberra man is on trial in the ACT Supreme Court charged with conspiring with another man to commit aggravated robbery at the Kambah Village Woolworths in January last year.

His co-offender pleaded guilty and received a discounted sentence in exchange for giving evidence for the Crown at the other man's trial.

He also received indemnity from prosecution for a spate of other unconnected offences after agreeing to give police a statement about those crimes.

Neither the accused man nor the witness can be named for legal reasons so for the sake of clarity The Canberra Times will call them Persons A and B respectively.

The Crown has alleged the pair armed themselves with a pinch bar and a knife.

Police, tipped off by a phone tap, ''jumped out of some bushes'' and arrested the pair as they scoped out their target.

In an interview shortly after his arrest, Person A told investigators the plan was a ''smash and grab''.

''I had no intention of doing this armed,'' he said.

''My intention was, I will be straight honest, my intention was I was going to wait until the shop closed, 10 o'clock, I was going to smash through the window of the shop … a smash and grab, you might say.''

Person A claimed to be unaware Person B had a knife and said the purpose of the pinch bar was to break through the window.

He said he was ''shattered'' to learn the other had the weapon, but that he didn't really know him - an acquaintance of three years - and ''he could have been a f---ing serial killer for all I know''.

But Person B said the other man knew about the knife, and that both knew two balaclava-wearing men with a pinch bar could inspire ''shock and awe''.

Person A told police he ''knew the law'' regarding armed robberies, and planned the crime so it would fall under a less serious charge if he got caught. ''I thought it was demand by menace, if that is even a charge,'' he said.

Prosecutor Shane Drumgold said Person A's ''misguided understanding'' of armed robbery laws was a ''red herring'' and an attempt to provide an innocent explanation.

But defence barrister Shane Gill said the Crown was applying more sophistication to his client's interview with police than Person A did.

The jury was told the plan was either to walk through the door or, if it was locked, use the bar to smash through a window.

Mr Drumgold urged the jury to consider what likely would have happened to the pinch bar after either scenario.

''[Does Person A] say 'well, I'd better not take this in because we don't want this to be defined as an aggravated robbery, so we'd better leave the pinch bar there'?'' he said.

Justice John Burns will begin his directions to the jury on Wednesday.