f confusing overly-specific comemnt

Author: TheBlueMatt

lightning/src/ln/channelmanager.rs

@@ -473,7 +473,9 @@ enum BackgroundEvent {
 
 pub(crate) enum MonitorUpdateCompletionAction {
 	/// Indicates that a payment ultimately destined for us was claimed and we should emit an
-	/// [`events::Event::PaymentClaimed`] to the user iff no such event has already been surfaced.
+	/// [`events::Event::PaymentClaimed`] to the user if we haven't yet generated such an event for
+	/// this payment. Note that this is only best-effort. On restart it's possible such a duplicate
+	/// event can be generated.
 	PaymentClaimed { payment_hash: PaymentHash },
 	/// Indicates an [`events::Event`] should be surfaced to the user.
 	EmitEvent { event: events::Event },