I'm not even a fan of Lin Wood at all. But I believe "flipping" refers to people who actually got indicted, and then were granted immunity. Not witnesses. If the defense doesn't have any reason to call Lin Wood, there's nothing that can stop the prosecution from calling him as a witness. Doesn't necessarily mean anyone "flipped". He wasn't charged and isn't being given immunity for testimony against anyone else.

https://www.msn.com/en-us/news/politics/pro-trump-lawyer-lin-wood-says-he-didn-t-flip-on-former-president-in-georgia/ar-AA1h0UNx

I'm not even a fan of Lin Wood at all. But I believe "flipping" refers to people who actually got indicted, and then were granted immunity. Not witnesses. If the defense doesn't have any reason to call Lin Wood, there's nothing that can stop the prosecution from calling him as a witness. Doesn't necessarily mean anyone "flipped". He wasn't charged and isn't being given immunity for testimony against anyone else.