grammar - How can we determine the subject of 「彼{かれ}が来{こ}ないこと を知{し}りませんでした。」?

Consider the following sentence.

彼{かれ}が来{こ}ないことを知{し}りませんでした。

I really get confused in determining the subject. Which is the correct translation?

1. 
   

   I did not know that he will not come.

   
   
   


2. 
   

   He did not know about the absence.

   
   

Roughly speaking, most of the available answers said that the speaker is the person knows about that thing.

However, today I found almost the same sentence quoted from

A Handbook of Japanese Grammar Patterns for Teachers and Leaners on page 317-318,

as follows.

Its translation is apparently contrary to the analysis given in the existing answers. ^{_{I am now in a critical position but committing suicide is not my option.}}

Answer

This sentence can technically mean both, but it usually (or almost always) means 1.

To mean 2., we normally say

彼は来ないことを知りませんでした。 = He didn't know about the (someone else's) absense.

because 彼 is the topic of the whole sentence.

In other words, the use of が after 彼 more or less indicates that "彼がこない" is the relative clause which modifies こと.