Take a look at https://github.com/code-423n4/2024-08-wildcat/blob/fe746cc0fbedc4447a981a50e6ba4c95f98b9fe1/src/types/LenderStatus.sol#L36-L38
This function is used to know if the lender has a credential, issue however is that expired credentials would also return true for this check, considering the check here is against the lastApprovalTimestamp being more than 0, but when granting the credential the lastApprovalTimestamp is set to non-zero. 
A lender with an expired credential would pass the has credential check.
Assume expired credentials to be no credentials
