I don't read much into the handbag thing either, other than the fact that they and the police made a mistake.
From their point of view, they have been informed of/witnessed, a hideous tragedy. They had no reason to believe that Oscar killed Reeva through anything other than an awful accident. I can imagine two reasonably young and inexperienced people thinking that it's the least they can do - to return this very personal item to a grieving woman.
I'm not prepared to leap and say that they removed it for any untoward purpose. Yes, they shouldn't have taken it, but that doesn't paint them as being some part of a conspiracy.
Don't get me wrong, when I first heard it, my reaction was 'they did what?' but in an 'Oh dear, that's not good!' way, rather than an 'I wonder why' way.
I'm currently transcribing the first session. Man his plea explanation is long!