Baroness Scotland - a question

Something doesn't smell right about this story.

Baroness Scotland's cleaner was apparently originally here on a student visa and then apparently overstayed the length of her visa. This would mean, I assume, that on the relevant page of her passport would be the student visa stamp stating clearly she wasn’t able to work.

As I understand the case, Baroness Scotland is saying that this was a "technical breach" because

"I did check absolutely everything. The critical thing is having checked, each employer is asked to take photocopies. I didn't take photocopies. I absolutely believe she was bona fide"

So Baroness did check all the relevant documents but neglected to take photocopies? If that is her defence then surely it means that one of the following is true:
1) that Baroness Scotland looked at the passport and either didn't spot that it was a student visa and that the visa had expired, which would make her incompetent (after all immigration related employment law was her area when she was at the Home Office)
2) that she did not look at the relevant page on the passport and has therefore lied to the UK Borders Authority
3) she did look at the page and it had been altered

Which of these is Baroness Scotland relying upon?

Maybe someone could raise these points with the "noble" lady should she deign to be interviewed by the media. I suppose that a really suspicious person might deduce that it is possible that Baroness Scotland took no photocopies because she knew there was a visa problem...