There's almost nothing worse than not knowing. A CPA can confirm that there was embezzlement, or that there wasn't. In a situation that our firm was called in for recently, an administrator had been let go a few years previously based on suspicion of embezzlement. Then that person began to work with another church, again overseeing financial transactions. When the first church heard of their previous administrator's new role in another church, they decided that they needed to know for sure about their suspicion of embezzlement so they could warn the other church and help to protect their ministry.
Most churches talk about integrity and accountability.
Many work hard at ensuring that the administration of their finances are not lacking in any way. Yet a surprisingly high percentage of churches don't do all that is required in many financial management areas. Unfortunately, many church boards or senior pastors don't want to do all that's required for correct financial management. We're not going to do that. And once they find out what it is, they don't want it.