It is good to add a require() statement that checks the return value of token transfers or to use something like OpenZeppelins safeTransfer/safeTransferFrom unless one is sure the given token reverts in case of a failure. Failure to do so will cause silent failures of transfers and affect token accounting in contract.
Reference: This similar medium-severity finding from Consensys Diligence Audit of Fei Protocol.
PrePOMarket.sol#L121
PrePOMarket.sol#L123
Consider using safeTransfer/safeTransferFrom or require() consistently.
