She never forced him to speak up because the message never actually got delivered to him, they never returned home and the soilders never passed along the message, he revealed that Tracy was the one all along on his own, although he could of spoke up sooner that's true, he must of felt pressured and afraid he would get harmed again.
But it was mentioned that the guards forgot to deliver the message to Oleg thus it only means Oleg voluntarily confessed when he got the opportunity to do so.
As a reference you can read chapter 43 again
Why are we protecting Oleg, don’t get me wrong I love and believe that he should get his redemption arc since he’s just a product of his fathers horrible treatment, but the FL is correct. He had many chances to speak up but it took the FL to force him to say it. If she didn’t, would he have honestly spoken up? I completely understand why the FL still treats him like that, it doesn’t matter if he’s a child it has been shown many times that he knew he didn’t deserve the praise but he still kept silent. I’m looking forward to seeing his changes tho