Would it be possible to get a cut deep inside the vaginal wall after a LS-CS?

My daughter gave birth just over 2weeks ago now, and is having problems with bleeding & clots. She was admitted to the local hospital yesterday, and on examination they found a cut inside her vaginal wall, the doctor who examined her felt that this was quite strange as she had had a LS-CS and said that a cut like this could be expected with a normal vaginal birth.. He proceeded to remove a clot from the site, and advised her that the bleeding and clots were coming from the cut and not from her cervix.
She was sent home yesterday afternoon with a course of antibiotics!
Due to the above, we have a few questions....
How would it be possible for her to have a cut when she had LS-CS? Was it due to something they did whilst she was in theater that we have not been told about?
Or
Was it something to do with when they tried to break her waters, which they had a problem with?
Why did they not stitch the cut up?
Is this a normal thing to happen?

Any help on this would be much appriciated please.

Many thanks

Willows