A couple of thoughts, looking again at the detailed track of both the original approach, and the second, successful, one.
Both approaches seem to reach exactly the same point west of the shoreline, seemingly following a direction of travel very sympathetic with an approach to the international airport ( and most certainly not Juha).
The original approach turns left, and travels in that direction for some 35 seconds before adopting a course which is again sympathetic with the location of the international airport.
The reason for that left turn is not known to us, and I have no new theory to add to the speculation, but I would observe that if indeed the crew mistook Juha for the international airport based on the view out of the window, they would surely have been able to conclude immediately that a landing would not have been viable from their altitude. Had they nevertheless believed that it was, we would have expected to see more significant altitude loss during the 35 seconds than there was.
Also, and at the risk of sounding old fashioned, surely it it not at the crews discretion to make as significant a deviation from their course so close to an airport (s) without ATC clearance?
Finally, is it of interest that on the second approach, they still approached from left of the extended threshold?