Deleting a live flow ends the calls it has out on workers and drops what a removed node still returns, so a node that never returns gives its slot and process back and a late answer no longer recreates the flow's values; a cancel goes through the call's own inbox and is sent after the call's frame, so a service stopped right after starting no longer cancels before its serve

docs/code/workers.md

@@ -96,10 +96,11 @@ Source code travels with each call and compiles on the worker, so remote-only
 dependencies do not need to be installed on the engine. Calls to `emit`,
 `save_artifact` and `load_artifact` work there too.
 
-Cancelling a run stops its active node processes. A disconnected worker fails
-in-flight calls. While executing, the agent sends heartbeats every ten seconds;
-90 seconds without contact fails the call. Heartbeats do not reset the node's
-own silence timeout.
+Cancelling a run stops its active node processes. Deleting a flow does the same
+for the calls it has out, and drops an answer that still comes back. A
+disconnected worker fails in-flight calls. While executing, the agent sends
+heartbeats every ten seconds; 90 seconds without contact fails the call.
+Heartbeats do not reset the node's own silence timeout.
 
 Every call runs in a process group of its own. The agent kills the group when
 the engine ends the call, when the connection drops and when the agent stops,