Mr. Anderson was really confused as to the reason for Ryan's sudden outburst when he had been acting calm all along making him doubt if Selena wasn't that important to him after all.
And to say the truth, since the moment he recognized Dan as his b*stard son, he saw the chance to permanently have Ryan stop breathing down their necks and ending up destroying the family he had spent his whole life building, a thousand times better than the temporary compromise that the capture of Selena would bring.
Moreover, he couldn't be sure whether that woman was just a shield or smokescreen for Ryan, and he knew that if she wasn't, even if they hid her at the most secretive place, it wouldn't take long before Ryan found her with the great power and connections he held in his hand.