Nah that's because they locked a second "transporter beam" onto the pattern while it was in transit, thus basically making a copy. Normally it's supposed to turn your matter into energy in a specific pattern, then move that energy to another location and turn it into matter again.

Now, in my opinion, in our universe, the end result is the same - your continuous consciousness is interrupted/ended and an identical copy of you is created somewhere else. But we're talking about the star trek universe, where thoughts are apparently at the very basis of physics and can directly influence the universe, especially anything to do with "subspace". So it's safe to say that consciousness exists on an additional, metaphysical layer other than just your corporeal form.

Also, there are multiple cases of people being turned into "pure energy" and retaining their consciousness somehow, so I dont see how a transporter would necessarily be different.