The first is not offensively incorrect, colloquially, but I would prefer the second, especially in more formal settings.
“The” and “a,” despite being such universals, do have some idiomatic usages. “The epitome” means, roughly, “average.” The “the” in that usage confuses some people, who think that “the” means, necessarily, the ONLY. Just as one can be “the average housewife,” one can also be “the epitome of the american housewife,” each phrase meanly substantially the same thing, and neither phrase conferring any sense of uniqueness or specialness. The “the” in the OP is idiomatically similar, but I’d still use the “a.”
Now, speaking in a more specific situation, I might say, “She’s running late; she was the victim of a fenderbender on her way here.” In that instance, I’d call it a tossup, colloquially. I’d still err on the side of “a” in more formal written communication.
Interesting, and something I hadn’t thought about. “Epitome” means “an example of a class or type”, and I think including “the” implies it is an extremely good or classic example, i.e. “The epitome of the American housewife” seems to imply the woman in question is the best example of an American housewife, and is therefore unique.
On the other hand, I don’t think I’ve heard the word “epitome” used with “an” unless it means a summary of a larger work, such as in “an epitome survives for each of the lost books of Livy”. I know the phrase “the epitome of an american housewife” would sound funny to my ears, arguing I think for the idiomatic interpretation lissener cites…
Maybe the reasoning is this:
In the horrific attack against Mrs Bloggs, she was the only victim, so it’s OK to use ‘the’ in that case.
Similarly, if you were the only victim of that particular hit-and-run, then it is indeed accurate to say that you were ‘the victim’ of that hit-and-run.
But you can’t say that about general stuff that afflicts more people:
“She was the victim of the 1920 pandemic”
“He was the victim of Hurricane Katrina”