Interesting analysis, but by the end I was hoping to hear how this train was actually causing the issue, on the physical level. Anyone have information on that?
If you check the press release stated in the link, there is the explanation there
Further tests on PV46 by engineers from LTA, DSTA and Rohde & Schwarz showed that faulty train signalling hardware on PV46 was emitting erroneous signals in addition to the ones it was supposed to emit. These erroneous signals occasionally prevented trains travelling in the vicinity of PV46, including in the opposite direction, from properly communicating with the trackside signalling system. This loss of communications led to the activation of the trains’ emergency brakes.
That was some pretty cool debugging (hint hint)