hmmmmm....I thought the wife left the day before....how would she know about the phone call??
The article didn’t say she was going to be questioned about the phone call.
What the investigators are going to do is find out from her if there were mysterious things going on, if he spoke about things which could be connected to the plane being missing, if there were any changes recently in his actions or thinking or emotions, if he was meeting with people she didn’t know, if there were strange calls in the past ... and basically everything about him and his thinking and his interests and his contacts.
The wife may be the “mystery woman”.
She is seen moving out of the house that they share together the day before and then this happens.