In fairness, appearing to deliberately flash you, for example, may reasonably be inferred as giving informed consent. The argument that the target was deliberately flashing you, however, would require either an explicit statement after the fact that they admit to doing as much, or lacking any such statement because the subject is unknown, it would require that under the circumstances, it would have been expected and reasonable for the subject to have known about your presence and your intent to photograph them (ie, both yourself and your camera must have been plainly visible, and not concealed from their view in any way).
Wow... where's thought crime coming from? As I said... you measure intent of the person being photographed by whether or not the person ever gave any informed consent to photograph anything that was being covered up by clothing, as I said. No informed consent means no intent....end of story. What constitutes informed consent would, at the barest of minimums, require explicit verbal permission, and from the photographer's point of view it would be safer to obtain written permission, if they feel the person being photographed may want to deny giving verbal permission later.
Of course, all of this is subject to other issues which can affect the legal validity of any so-called informed consent, such as whether or not the person was under any sort of duress when they made such consent.
Because if not, it's not like any proof of the authenticity of their claim will make any difference at all.
If you ask me, I think that the necessary information about her itunes account and password, given that the device itself was bequeathed in her will anyways, should have been stored in a sealed envelope which accompanied the physical copy of the will.