does this mean it is incorrect to put "hai" in the sentence twice?
You could, but it's often omitted when the statement is negative.
It's only actually wrong on a "tap what you hear" question, because it's not in the audio. :-)
Otherwise, it's correct to omit it if you want.
Is है removed in the 1st part of the sentence because the statement is negative or because there is already है at the end of the sentence? Or both?
@ZelieZazou - Because the statement is negative. If the first statement was positive, then you will need to put है after the first statement too. E.g. Raj is eating because he is hungry = राज खाना खा रहा है क्योंकि उसे भूख लगी है
आपके जवाब के लिए धन्यवाद :)
Is it correct to say that native speakers omit the bindi in क्योंकि?