Who did you choose to take the fall for freeing the synths? Justin Ayo was a jerk but everything he does is for the Institute's sake, and he has never done anything illegal and all within the rules of the Institute. He was a bit wary of the Sole Survivor, but it was justified and he said that he was afraid that Railroad gets their hands on the Sole Survivor, he was smart enough to be wary about the Sole Survivor unlike Father and the rest of the Institute who were so welcoming that the Sole Survivor could be working for the thieves. Liam has a defying attitude that he could potentially become the head of the robotic in the future. He's smart but his attitude could mean that he could go behind your back in the future if he disagrees with your decisions. He could be a security risk for the Institute since he's also too naive and defiance, but for those who find Dr. Ayo to be a tyrant, it could be used as a good excuse to get Ayo out of the Institute. In the end, who do you choose?

Haven't had this option yet. I assume it's further on down the institute quest line.

On a side note, I really dislike Ayo.