持っていること vs 持っていたこと


When I was writing a composition in Japanese I wrote this sentence:

東京メトロでは、日本人は僕がとても重い鞄を三つ **持っていた** ことに気が付きましたから、荷物を持つのを手伝ってくれました

What I wanted to say is: In the metro, since Japanese people realized **I was
carrying** 3 bags which were very heavy, they helped me to carry the baggage

I got corrected the **持っていた** I wrote for **持っている** but what I wanted to say
is "I was carrying", that is, in the past. Why is it used in Japanese the
present tense? Is there a rule or something? I got confused because of that
and now I don't know when to use the present or the past in these kind of
constructions in Japanese, even when in English we use the past tense.




The problem here is time agreement. I first left a comment because I don't
feel very much confident at explaining it.

First, with ていた

> AはBがCを持っていたことに気づいた。  
>  A realized that B had been holding C.

Second, with ている

> AはBがCを持っていることに気づいた。  
>  A realized that B was holding C.

How so? The depend clause is subordinated to the tense of the main clause.
That does mean that if the tense of the main clause is past and the depend
clause is "present" then the action expressed by depend clause is at the same
time as the main clause. However, if the main and depend clauses end with past
tense then the past of the depend clause is older than the one of the main
clause.




The problem here is time agreement. I first left a comment because I don't
feel very much confident at explaining it.

First, with ていた

> AはBがCを持っていたことに気づいた。  
>  A realized that B had been holding C.

Second, with ている

> AはBがCを持っていることに気づいた。  
>  A realized that B was holding C.

How so? The depend clause is subordinated to the tense of the main clause.
That does mean that if the tense of the main clause is past and the depend
clause is "present" then the action expressed by depend clause is at the same
time as the main clause. However, if the main and depend clauses end with past
tense then the past of the depend clause is older than the one of the main
clause.

