   updateTimeOut = (updateTimeOut < updateTimeIn) ? updateTimeOut : updateTimeIn;

updateTimeIn ==0 ==>  (updateTimeOut < updateTimeIn)== false ==> result of the expression is updateTimeIn == 0 ==> updateTimeOut =0

function get(bytes32 base, bytes32 quote, uint256 amount)  external virtual override  returns (uint256 value, uint256 updateTime)  {
...
for (uint256 p = 0; p < path.length; p++) {
  (price, updateTime) = _get(base_, path[p], price, updateTime);

function _get(bytes6 base, bytes6 quote, uint256 priceIn, uint256 updateTimeIn)  private returns (uint priceOut, uint updateTimeOut) {
...
  (priceOut, updateTimeOut) = IOracle(source.source).get(base, quote, 10 ** source.decimals);    // Get price for one unit
  ...
  updateTimeOut = (updateTimeOut < updateTimeIn) ? updateTimeOut : updateTimeIn;                 // Take the oldest update time
}
