>but by recording sound, isn't he breaking the law
Depends on if it is a one or two party state, and whether or not he constitutes a party. In Oklahoma, for example, if you and I are on the phone I can record the conversation without notifying you. In some states (New Hampshire, I think, off the top of my head) all parties to the conversation must be informed.
If he is partaking in the conversation or within earshot, he might be considered a party, and might be okay.
Depends on if it is a one or two party state, and whether or not he constitutes a party. In Oklahoma, for example, if you and I are on the phone I can record the conversation without notifying you. In some states (New Hampshire, I think, off the top of my head) all parties to the conversation must be informed.
If he is partaking in the conversation or within earshot, he might be considered a party, and might be okay.
I am not a lawyer.