A failed write says so

Steps

1. 1 None Offstage: provisioning an event to sell (the instance had none on sale) 0:01
2. 2 Member A member puts a ticket in the cart 0:12 ▣

   411px — a phone, where a silent reload is completely indistinguishable from a dead button.

3. 3 Member Offstage: the ticket goes into the cart 0:14
4. 4 Member The cart, with the ticket in it 0:18 ▣

   One line, one Remove button. Everything below happens without this page being reloaded — which is the point.

5. 5 Member Offstage: another device empties the cart 0:19
6. 6 Member Press the button that is now stale 0:20 ▣

   Before plan 128 this reloaded as though it had worked. The item was already gone, so the page even looked correct — which is exactly how a silent failure survives review.

7. 7 Member The helper hands back an outcome, never a bare body 0:22

   `{ok, status, code, message, data}`. The old helper returned the parsed body and discarded `res.ok`, so there was nothing to check and nothing to paint.