It is more likely that he has been advised by his lawyer to get a lawyer with no conflict of interest.
It is not always possible for a lawyer to represent two clients in the same case as sometimes their interests conflict.
That does not necessarily mean that either of them is guilty.
I am not a lawyer, but I am aware that this happens frequently.
I dont think it was the same lawyers... it was an agreement to share info between Flynn’s lawyers and Trump’s lawyer