ILS= Instrument landing system
Unless you are flying an aircraft with a full FD/AP system capable of flying a coupled approach how are you able to look outside, other than a quick glance?
I think its fair to say that 99% of people flying an ILS expect total protection on an ILS approach, it matters not that the conditions are visual or IMC you are flying a PA.
If the 402 was cleared for the ILS then there should have been no conflicting traffic period, i will leave the rest to the AAIB...........RIP Guys