Pure speculation of course , but if it was a NPA perhaps they got the lights @ low altitude and were attempting to manouvere at low level in poor vis to get a landing out of it it.
Never easy, and the pressure on them to get in, evidenced by the fact it was their 4th attempt ,would no doubt push them to give it a go even if it looked nigh on impossible.
Poor guys, talk about between a rock & a hard place.