Serious question: if you said, "I want a cup of clam chowder" and the restaurant ignored your order and cooked you a Delmonico style aged steak and Maine lobster, and charged you for it, would you laugh and just pay the $200 tab?
I don't think this is really different, legally or morally speaking. If a service behaves in a way that is contrary to instruction, the client should not be liable.
I told Fable 5.2 to do code review of my entire codebase, make the plan for all the fixes, then offload the fixing to Opus 5.5. It launched 50 review agents (all using Fable 5.2) and drained my $200 plan weekly Fable limit in 90 seconds 🤣
commit f1562d6
It didn't behave contrary to what I told it. I specifically told it to use Fable 5.2 for all the review subagents. I didn't realize it was going to drain my usage that fast. This was my mistake.