Ok, let me ask about more specific scenarios then and we can see which pieces of this I’m missing:

Let’s start with a really simple one to make sure we are on the same page:

Let’s assume a mining pool with 70% of the hashrate, but no mining users in the pool with the DC full node, the pool OP writes a transaction that includes a bunch of honest transactions, but one malicious one that pays out of the DC like 10k BTC to themselves. Then they put it in the mining pool’s blocks and everyone starts blindly ACKing it without realizing.

What is it about the transaction/nodes/etc that prevent this transaction from either being written, or prevents it from being confirmed?

(I realize this is unlikely and I don’t want the normal “it won’t happens because” arguments, I want this played out so I can understand how it works)