What's the difference here: Hey, sorry, I've been so busy at work. VS Hey, sorry I

[B45]

What's the difference here:

Hey, sorry, I've been so busy at work.

VS

Hey, sorry I've been so busy at work.

Are both okay?

 

[Grumpy]

In the first instance, we don't specifically know what the speaker is "sorry" about. The phrase "I've been so busy at work" is an explanation/excuse relating to whatever it is that the speaker is sorry about. So the speaker may be saying "I'm sorry I haven't called you. I have been so busy at work that I haven't had time".

In the second instance, the "sorry" relates specifically and exclusively to the fact that the speaker has been so busy at work.