Ms Evans, a Marine Corps veteran who had appeared on the show during the annual Veterans' Week special, ended up progressing to the next round – when a similar potential stuff-up again occurred.
She appeared to request the letters "B", "H", "D" and "A" – but when the host asked her to confirm whether the third letter was a "D" she corrected him and said it was a "B" – before changing her mind and insisting it was a "D".
Ms Evans did not win that round but ultimately went home with prizes worth $US19,800 ($A28,856).
Twitter has been flooded with complaints from viewers who are convinced the Wheel of Fortune host misheard the contestant and effectively handed her a win.
Some have even called for Sajak's resignation over the incident.
"SHE SAID B!!!!! NOT D!!! She shouldn't have won this round Pat!!! Wow," one Twitter user posted, while another wrote: "I'm sorry does this guy not understand his letters. This is the second time! Come on!!!"
"He's been hosting the show for 36 years and can't distinguish a clear B from a D? Maybe time to retire …" another said, while another claimed: "OMG this is outrage! Her winnings should be taken away! She said B."
However, Ms Evans has weighed into the debate, hitting back at Twitter critics and insisting she said "D" all along.
When one Twitter user claimed the woman had "Definitely said B. as in bullsh*t", Ms Evans responded with: "Nope. D as in Definitely said D."
Co-host Vanna White and host Pat Sajak make an appearance at Radio City Music Hall. Photo / AP
Wheel of Fortune debuted on US TV screens in 1975, and Sajak has hosted since 1981.
The 73-year-old was recently temporarily replaced by hostess Vanna White as he underwent emergency surgery "to correct a blocked intestine", according to the Wheel of Fortune Twitter account.
However, it's not the first time a game show blunder has made global headlines.
In July this year, popular UK quiz show Countdownleft its hosts red-faced — and fans in stitches – after one seven-letter clue took a "risky" turn when co-host Rachel Riley uncovered the letters "N", "R", "W", "A", "E", "K", "S", "O" and "M" during an episode.
Two contestants who had to rearrange the letters to make a new worth both submitted the term "wank*rs", drawing audible laughs from the audience.
And in January this year, TV legend Jeremy Clarkson – the host of the UK's version of Who Wants to be a Millionaire? – was accused of cheating by helping a contestant on air.
And back in 2001, another major scandal rocked Who Wants to be a Millionaire? in the UK when Charles Ingram was a contestant on the program with his wife Diana and friend and university lecturer Tecwen Whittock in the audience.
The group devised a scheme to ensure a million-dollar win, with Mr Whittock coughing to indicate the right answers and blowing his nose when wrong answers were read.
He ended up winning the lot but was later forced to hand the cash back and was also convicted of deception in court.
And in 1999, contestant Tony Kennedy scored £64,000 ($A114,432) after his incorrect answer was accepted as correct.
He was asked, "Theoretically, what is the minimum number of strokes with which a tennis player can win a set?" and given four possible answers – 12, 24, 36 and 48.
