Lawyer here. I find the allegations quite troubling (although I haven't seen the TikToks and I haven't followed any of this too closely).

 Anything he says right now that makes him look even a little bit bad ("I bought her shots") can be used against him in a lawsuit or criminal action. Meanwhile, anything he says in his defense would get thrown out as inadmissible hearsay. Addressing these allegations might be a good moral decision, it might be a good reputational decision (if he accepts some responsibility or provides some serious evidence against the allegations), but it's a terrible legal decision.

 And maybe he wants to take responsibility for that 60%. But I guarantee you his lawyers are telling him not to because then that 60% will be used against him but his defense against the other 40% will be thrown out because it's hearsay.

The court of public opinion is absolutely brutal on the accused.  One side gets to tell their story while the other side just has to shut up under the advice of their lawyers. Depp v. Heard.

I can't be sure what happened in the past, but I am confident about what's happening right now: Andrew is being silent because his lawyers said he needs to.