The phrase "actually mistakes" is correct and usable in written English.
It can be used to emphasize that something is indeed a mistake, often in contrast to a previous assumption or statement.
Example: "I thought I had completed the project correctly, but upon review, I found that there were actually mistakes in my calculations."
Alternatives: "truly errors" or "genuinely blunders".
Most of the "lies"—almost all of which are actually mistakes or misrepresentations, not deliberate falsehoods are products of the endless spin and interpretation of America's "permanent campaign".
Actually, mistakes like these often help many of us grow as investors.
She is named after her majesty the queen, and on occasion actually mistakes herself for the aforementioned monarch.
Unfortunately when they first meet, Dave actually mistakes a photo of Madeline Albright for Leslie's grandmother causing her to reconsider whether she wants to date someone less informed than herself.
Obviously, my nurse and radiographer didn't actually mistake me for Wayne Rooney.
All smoke and smoking is banned because of the notion (which is actually mistaken) that there were smoking crematory chimneys.
Becky Milligan: And then of course, the man, the victim, who was in the film on Newsnight, Steve, Steven Messham, he released his statement saying this was actually mistaken identity and the man who he thought was you was not in fact you.
If you tried 15 things that didn't work and one thing that did work and didn't talk about the 15 that didn't work, then the statistic that makes it significant is actually mistaken.
For example: "A west-country gentleman, not much acquainted with the ways of London, expressed great surprise, a few nights ago, at the flocks of chicken prostitutes which he observed before Somerset House, and which he actually mistook for the pupils of some large boarding-school.
Yet that widespread belief is actually mistaken.
Note that this conclusion is consistent with the view that one of the parties is actually mistaken.
