I'm not so sure about M1. Even if she did perjure herself, I think it would be transparent - even though I do think she's being groomed to lie for him. She seems like an innocent to me. I could be dead wrong. IF she were called, she'd be confronted with her statements to LE and whether she was lying then or lying now, if she were to choose to deny her previous statements.
Barry's incessant lies about everything - especially his alibi, the state of his marriage and the discovery of Suzanne's texts (to mention just the tip of the iceberg) point to only one thing. Barry murdered Suzanne.
What the judge deems admissible is quite another story. I'll be looking at him BIG TIME to explain the reasons for his rulings, but as we all know - you can't unring a bell. [Enter appeals attorney, stage left]