The phrase "actually a case of" is correct and usable in written English.
It can be used to clarify or specify that something is indeed an instance or example of a particular situation or phenomenon.
Example: "What seemed like a simple misunderstanding was actually a case of miscommunication."
Alternatives: "truly an instance of" or "genuinely a situation of".
This may seem counterintuitive, but it's actually a case of simple market competition.
The previous deadliest anti-Semitic attack, the ADL said, was actually a case of mistaken religious identity that claimed four lives.
Leaving aside the fact that many of our town and city centres are already architecturally terrorised by fortresses of shopping, it's actually a case of so far so good.
During the thirties, Tallulah had entered the hospital for what was announced as an "abdominal tumor" but was actually a case of gonorrhea — contracted, she was to say, from George Raft — so violent it brought her close to death.
It is certainly not easy trying to decipher what goes on inside Daniel Levy's head sometimes but, then again, I would be pretty sure the Spurs chairman could put up a reasonable counter-argument that it is not actually a case of whether someone necessarily deserves to be sacked.
Bach has claimed that the Gricean picture of referential intentions can deal with this sort of case by deeming only the latter intention 'genuinely referential', Reimer that the speaker's gesture constrains which of her intentions is relevant, and King that this is actually a case of reference failure.
My favourite video of all time is actually for James Blake's A Case Of You, the one that has Rebecca Hall in it – I can't watch it without my entire body shaking.
"It was actually more a case of collusion," he said.
Yet, what had been assumed to be teething problems – the laborious build-up, blunt attack and a surprisingly porous defence – actually proved a case of terminal decline.
"It's actually just a case of your promoter saying, 'Would you like to play Cardiff?
In other words, the supposedly "weak" form of contraposition is actually not a case of contraposition at all.
