One of the protesters cleared of an attack on the Waihopai Spy base says it would be extreme to change the law in the light of his case.

Adrian Leason told the Herald it seemed excessive for Prime Minister John Key to be talking about the possibility of change to a long-standing piece of common law.

"I guess the establishment is not used to having setbacks like this, and when it does it's not used to needing to be a good sport."

"Maybe there's pressure coming on the Prime Minister from other sources, but that seems a very extreme reaction to a piece of common law justice."

The decision to acquit the Waihopai saboteurs surprised Mr Key who said yesterday he was not ruling out a law change.

Teacher Mr Leason, 45, Dominican friar Peter Murnane, 69, and farmer Sam Land, 26, were acquitted last week on charges of burglary and wilful damage at the Government Communications Security Bureau (GCSB) base at Waihopai, in Marlborough.

After cutting through alarmed, electric fences without setting off any audible alarms or getting electrocuted, the men reached one of two inflatable domes covering satellite dishes, placed their hands on the plastic skin and said "we disarm you in the name of Jesus Christ", before slashing it with sickles.

The three said they were saving lives in Iraq by disrupting satellite transmissions and were acting for the greater good. A jury in Wellington District Court found them not guilty.

Mr Key said Justice Minister Simon Power may seek advice on legal issues raised about the defence used and whether it should be used.

"If that ruling was to stand does that set a precedent and if so does the law need to change in New Zealand like we changed the law around provocation?"

Mr Leason said: "It's probably a little bit of a reminder that in the corridors of power, people are displeased.

"When the little people get a win, it does send some shudders down a few corridors [of power], and maybe in New Zealand we feel okay about that. Every once in a while, that's an okay thing to do."