Well, "the" is the definite article. You can't see it in the Hungarian sentence. Since its very nature is to be definite, you can't just omit it, right? Usually. The same is true for Hungarian.
So, the sentence must be indefinite. Which is "a reporter" in English, and "egy riporter" in Hungarian. But that "egy" can be omitted. In fact, it is omitted quite frequenty. As in this sentence.
So that's why.
These two are very much the same:
- Én riportert várok kint.
- Én egy riportert várok kint.
The "the" version would be this:
- Én a riportert várom kint.
See, even the conjugation of the verb is different in this case.