Multiple rounds of "continuing action" conjugations


I got this question from a JPLT quiz app:-

> ドラマを見つづけていたら、朝になってしまいました

I'm guessing it means "As I was watching the drama, it became morning", but
noticed both clauses go through the "continuing action" conjugation multiple
times. Wouldn't a simpler way of saying that be:-

> ドラマを見つづけたら、朝になりました

What other nuances are being implied here?




> ドラマを見つづけ **ていたら** 、朝になっ **てしまいました** 。

The ～ていたら indicates that something happened while you're doing the action,
meaning "while I was doing~~", and ～てしまいました indicates an unintended result or
the speaker's regret.

Examples:

  * テレビを見 **ていたら** 、電話が鳴った。  
While I was watching TV, the phone rang.

  * ガラスを割って **しまいました** 。/ ガラスが割れて **しまいました** 。  
I (unintentionally) broke the glass. / The glass broke (and I feel sorry about
it).

* * *

> ドラマを見つづけたら、朝になりました。

This sentence has lost both of the meanings/nuances of "while I was doing~~"
and "unintended result or regret". And ドラマを見つづけたら part sounds a little
unnatural to me, because it sounds like "When/As I continued watching dramas,
morning came", "I continued watching dramas, and because of that / as a result
of that, morning came."

Example:

  * 触っ **たら** 、壊れました。  
I touched it, and (because of that,) it broke.

  * Cf: 触っ **ていたら** 、壊れました。  
While I was touching it, it broke.




> ドラマを見つづけ **ていたら** 、朝になっ **てしまいました** 。

The ～ていたら indicates that something happened while you're doing the action,
meaning "while I was doing~~", and ～てしまいました indicates an unintended result or
the speaker's regret.

Examples:

  * テレビを見 **ていたら** 、電話が鳴った。  
While I was watching TV, the phone rang.

  * ガラスを割って **しまいました** 。/ ガラスが割れて **しまいました** 。  
I (unintentionally) broke the glass. / The glass broke (and I feel sorry about
it).

* * *

> ドラマを見つづけたら、朝になりました。

This sentence has lost both of the meanings/nuances of "while I was doing~~"
and "unintended result or regret". And ドラマを見つづけたら part sounds a little
unnatural to me, because it sounds like "When/As I continued watching dramas,
morning came", "I continued watching dramas, and because of that / as a result
of that, morning came."

Example:

  * 触っ **たら** 、壊れました。  
I touched it, and (because of that,) it broke.

  * Cf: 触っ **ていたら** 、壊れました。  
While I was touching it, it broke.

