Sorry about that spoken language phrase
Said when someone realizes or thinks some mistake they have made is not serious although it may not be so
Oh, I'm sorry about that. I didn't know you were using it.
A: "Hey, you drank my last Coke!" B: "Oh yeah, sorry about that."
After what she had done to me, she just said, "sorry about that."
used when you feel that did not feel guilty as you did nothing wrong