He revealed that the Spicers were originally accused of receiving two ounces of P worth around $24,000. Anything above 5 grams is considered for supply purposes according to the law.
However police now say the amount the couple received from former North Shore real estate agent Brett Campbell Bogue to supply "clients" during a Bathurst race weekend is unknown.
Mansfield criticised police for backtracking on their original claim, suggesting they were "desperate" to get a favourable outcome.
"These charges fail on so many levels it isn't funny.
"[Tonya Spicer] wasn't a dealer, she wasn't giving it away or selling it. She wasn't an addict. She didn't possess it or use it, and she was truthful in her affidavit."
Mansfield told the court claims the couple spoke in "code" to Bogue, who was convicted of serious drug dealing charges in 2014, were nonsense.
He rejected suggestions a text message from Tonya Spicer to Bogue asking him to bring "pudding" to a dinner party was a clandestine reference to P.
"I don't think there is anyone in this room that hasn't been asked to bring something when they go to dinner, whether it's a cheese platter or bottle of wine.
"What was it? It was dinner, dessert and a few wines."
Mansfield said drug squad officers searching intercepted communications for drug references were likely to find them, even in totally innocent conversations.
Innocuous message to Bogue from the Spicers such as, "Can I see you" or, "How you looking" were not drug code, Mansfield said.
"Where is the discussion regarding quantity? Where is the discussion regarding how much a deal might cost? Where is the discussion about ... how it might be consumed?"
There was no evidence of Tonya Spicer "snorting, smoking or ingesting" P and no evidence that the couple supplied meth to others.
"It's a drug trial which sadly has got some media attention. It's the very kind of hearing that no one wants to be associated with in the kind of way that Mrs Spicer has been dragged into Mr Bogue's drug dealing."
He reiterated that while the Spicers were old friends of Bogue, they had no idea he was involved in a large scale methamphetamine supply operation until he was charged by police in late 2012.
Supposed drug references alleged by the Crown could be explained by the Spicers making legitimate attempts to recoup a large debt owed by Bogue for work done by Paul Spicer's paint and panel business. Others related to a real estate deal or simply trying to catch up with an old friend.
The Crown case
Earlier, the Crown set out its case against the Spicers, saying the couple were "desperate" to source the drug from their dealer to share with "clients" in the Far North.
Crown prosecutor Brett Tantrum told the jury the Spicers used real estate terms such as "contracts", "sale and purchase agreements" and "listings" as code for drug deals.
"It's not the Crown's case that the Spicers were massive drug dealers in the Far North. What is the Crown's case is they regularly sourced meth for themselves."
While the Crown did not know how much of the drug the Spicers purchased from Bogue, that did not matter.
"I don't have to prove how much was supplied, but just that they had it with the intention to supply some of it to others."
Tantrum addressed key pieces of evidence from a transcript of communications between the Spicers and Bogue, intercepted by police during a 2012 drug squad operation codenamed Enzone.
In one conversation, Paul Spicer tells Bogue, "We've run out of supplies", to which Bogue replies, "Oh yeah, it's a bit light but we'll sort something".
Tantrum told the court this communication "in my submission to you is a message to Mr Bogue that he wanted some more drugs. It's not about the money."
In another message, Paul Spicer tells Bogue "mama's f***ing hovering".
Bogue replies: "Yeah, probably not worth it at the moment."
"What nothing?" Paul Spicer asks.
"Na," Bogue responds.
Tantrum told the court the conversations took place around the time Bogue's associates were manufacturing their next batch of the drug in Kaitaia.
"Mr Bogue says it's probably not worth it at the minute but probably Monday will be good. He's hoping that by Monday Mr Bogue will have received his fresh supply of meth from up north."
Tantrum told the court the communications showed the Spicers' growing desperation for the drug, with constant phone calls and text messages to Bogue to "catch up" and asking "how you looking".
A later message from Bogue said: "I'm up in Walky [Warkworth] and I think I've got that listing you've been waiting for all week."
"That's code for methamphetamine," Tantrum told the jury.
The trial continues.
