The phrase "a small slip" is correct and usable in written English.
It can be used to refer to a minor mistake or error, often in a casual or informal context.
Example: "I made a small slip in my calculations, which led to the incorrect result."
Alternatives: "a minor error" or "a slight mistake".
Another conservator pulled a small slip of torn notebook paper from one of the baths.
After a small slip – a wonky mapping app – the machine went into reverse.
Only Arizona have a better record than Green Bay, but with Carson Palmer out of the picture, a small slip could send the NFC through Wisconsin.
What this piece of art also shows is the danger of even a small slip when you're the one who has to do all the pushing.
We were given a small slip of paper with a presentation topic and a time to attend a one-hour interview in the morning.
On a small slip of paper filed with a hand-written letter, Reagan wrote: "turn it over to the gals for typing & mailing.
It was a dangerous assumption, as he found to his cost when a small slip-up on the US/Mexico border in May 2009 ended up with him stranded in the north-west of England, an alien once more.
When Michael finally announced his decision at the Italian Grand Prix in Monza, a small slip-up renewed speculation - the press office wanted to be professional and fast and issued the press release with the news of the retirement immediately after the race.
Via a small slip-up in information security Google has clued everyone in on some new features which are being developed for the popular Gmail service.
A small slip-up in common courtesy might just have been 84-year-old Gloria C. Mackenzie's lucky ticket.
At the same load level the bars in SCC tend to present a smaller slip than in VC.
