The original Greek presents problems for translators, since the words do not always translate exactly word for word, and many commentators realize this. For instance, according to some theologians, in the case of John 8:58, the structure "before" does not carry any indication of tense in Greek, and they have considered there is a more natural rendering to the phrase. Greek and Hebrew do not always translate as we understand. The phrase "Before Abraham, I am," itself is not a normal expression. I am can mean I exist, and even literally does not mean that Jesus is without beginning, equal to the other two persons said to be in the trinity.
Important also to the subject, the words YHWH (Yahweh or Jehovah) and "I am" (ego eimi) are not interchangeable. Just as LORD is said by many to be interchangeable with YHWH but it's not. It is VERY misleading to substitute LORD for YHWH (Yahweh or Jehovah, as some English translators have it). But in the case of ego eimi, does not mean that Jesus is God without beginning, equal to the other two persons. More language technicality can be gone into.