SAR - Type of Suspicious Activity?

Looking for guidance on the type of suspicious activity to note on a SAR.

A customer conducted a large cash withdrawal, over $10,000. The teller inquired on the reason for the withdrawal, and the customer stated it was a gift for his children because cash is not traceable.

Tax Evasion? Something else?

Any feedback is appreciated.

If that is the only suspicious piece and a CTR was filed, I wouldn't file an SAR. If he had broken it up and I was already filing for structuring I may add Tax Evasion because of the comment, but I don't think that comment alone is SAR-able.