The 80-year-old pensioner was cleaning up raw sewage bubbling up through her shower pipes.
It's the worst case of "cowboy" operators endangering homeowners Martin Sawyers can remember in his two years as chief executive of the Plumbers, Gasfitters and Drainlayers Board (PGDB).
It's not just the health and safety aspect when cowboys roam the range of sub-standard work; homeowners can find themselves saddled with huge bills if the cowboys' handiwork causes the insurance company to reject liability.
By law, homeowners and landlords must hire authorised plumbers, gasfitters and drainlayers for a wide range of restricted tasks.
But that doesn't always stop the cowboys or people looking to do it cheaper, says Sawyers, like the 80-year-old recently confronted with sewage on her shower floor.
"It wasn't just that the poor woman was having to clean it up all the time nor that she was 80; it was a real danger to her health."
The problem occurred after an unauthorised tradesman laid a soil pipe to the mains to carry foul water from the premises. After the defective work, sewage backed up and entered her shower.
The man involved was taken to court, where he was fined $2400 plus court costs and a solicitor's fees for illegally carrying out drainlaying work - part of the PDGB's role is to prosecute unauthorised tradesmen.
While there was no insurance blowback in the case of the 80-year-old, a couple in Wellington in 2011 were left severely out of pocket when their cowboy herded 13,000 of their dollars into his saddlebags for an upgrade to a bathroom and ensuite.
After the job dragged on for many weeks, the homeowners declined to pay any more. They did not see the man again - but they saw the results of his labours: the toilet leaked raw sewage, water was leaking onto wires and down the walls and the ceiling was stained. Wallpaper started peeling and they noticed staining spreading to a downstairs bedroom.
The unauthorised tradesman was fined $3800 and $245 costs for carrying out plumbing without being registered or licensed.
Unauthorised workmen can present compelling cases; the man in question told the couple he wasn't a registered plumber but they had seen him praised in a building magazine and had already done a good job for them on their roof.
However, in the wash-up to the bathroom saga, the wife told the Stuff website that they had ended up paying $50,000 to get the bathroom they wanted - saying they were paying interest on the $50,000 but stood only to gain $20,000 from the man's insurance company.
"Our lives have been in upheaval for 18 months," she said at the time.
Sawyers says, far from being isolated incidents, cowboys in court have generally increased in recent years: "It's a buoyant construction market and, unfortunately, when some people see the chance to make a dollar, they are into it.
"We have also seen, even more unfortunately, some taking advantage of homeowners in earthquake zones. After the Christchurch earthquakes in 2010 and 2011, there were instances of people offering plumbing services when untrained and unlicensed - and we issued a warning to that end when the Kaikoura quake happened as well.
"I think the numbers going to court might have increased too - because we are getting better at detecting them [cowboys]."
A key tool was the Report A Cowboy (RAC) app launched last year, downloadable from the PGDB website. There are no figures available to compare from previous years but 126 complaints were laid over the app last year with 15 so far this year, with over 10,000 downloads of the app. Just under half the complaints involved allegedly unauthorised plumbers.
Sawyers said an awareness programme called "Sort the pros from the cons" had also helped make homeowners and landlords realise they had only to ask for a registered tradesman to produce a licence card issued by the PDGB to be sure they were dealing with a bona fide professional.
"Keep safe and avoid dealing with any service providers who cannot produce a licence card issued by the PGDB," he says, "and if you have any suspicions or want to report some alleged wrongdoing, use the RAC.
"We are not doing this to protect plumbers - it's to protect homeowners. Plumbers take four years to qualify and there are good reasons why it takes that long. A lot of the work they do is skilled, simple as that.
"And if you engage a cowboy, you are more than likely also starting the clock on a ticking time bomb," he says. "It will likely go off at some point and cost lots more to fix it.
"It might not go off when you are living in your house but, if you sell, you are just handing over the time bomb to someone else and there could be repercussions."