What you may not have been told about conditionals is that there are many instances where we mix conditionals. There are actually more than the 4 conditional types which appear in textbooks. Mixed conditionals are both correct and common. In this case, however, you are right. As your example is a Type 3 Conditional (a hypothetical past scenario), it should be 'if if hadn't been...'. But does this mean that what the speaker said was actually wrong? Not necessarily. It certainly wouldn't sound like a mistake to the majority of native speakers. This is because there are a number of non-standard variants when it comes to conditionals. For example, you'll also come across native speakers saying things like "... if it hadn't've been 9.4" with an extra 'have' in the 'if' in clause. Many AmE speakers, I believe, also use the past simple in third conditionals, even though this is technically incorrect according to standard grammar rules. Remember that native English speakers are not taught the basics of English grammar in school. English-speaking children learn their mother tongue by copying the patterns that they hear around them, and, by and large, they carry on using those same patterns all their lives. If their family and their peers speak standard English, the child will grow up speaking 'correct' English. But if they grow up in an environment where non-standard English - such as using 'lay' instead of 'lie' - is spoken, that is how they will continue to speak. A speaker may drop or learn to correct certain non-standard features which bear a social stigma, such as the use of 'ain't'. Other features, such as non-standard conditional forms, are less obvious. You'd lose a mark in a grammar exam for writing either 'wasn't 9.4' or 'hadn't have been 9.4', but in everyday spoken language these non-standard forms would probably go unnoticed.

I think the type 2 conditional is being mixed up with the type 3 or 4. Yes, if English is not your major, you might get this wrong, but also, we do use this a lot in speech or even written articles - we are not really fussed about getting everything absolutely correct a lot of the time:) If the writer were to have used an English editor, he might actually have been corrected! :)

A mistake from proper grammar point of view. There are 2 mixed conditionals with the same formula but neither of them can be applied here due to the context.