diff --git a/lib/statifier/actions/assign_action.ex b/lib/statifier/actions/assign_action.ex
index 6a04886..24e18bc 100644
--- a/lib/statifier/actions/assign_action.ex
+++ b/lib/statifier/actions/assign_action.ex
@@ -94,16 +94,13 @@ defmodule Statifier.Actions.AssignAction do
 
       {:error, reason} ->
         # Create error.execution event per SCXML specification
-        error_event = %Event{
-          name: "error.execution",
-          data: %{
+        error_event =
+          Event.internal("error.execution", %{
             "reason" => inspect(reason),
             "type" => "assign.execution",
             "location" => assign_action.location,
             "expr" => assign_action.expr
-          },
-          origin: :internal
-        }
+          })
 
         # Log the error and generate error.execution event per SCXML spec
         state_chart
diff --git a/lib/statifier/datamodel.ex b/lib/statifier/datamodel.ex
index acfde52..5059c3f 100644
--- a/lib/statifier/datamodel.ex
+++ b/lib/statifier/datamodel.ex
@@ -102,13 +102,13 @@ defmodule Statifier.Datamodel do
   Set a value at a nested path in the datamodel.
 
   Takes a datamodel, a list of path components (keys), and a value.
-  Creates intermediate maps as needed for nested assignment.
+  Does not create intermediate maps as needed for nested assignment.
 
   ## Examples
 
       iex> datamodel = %{}
       iex> Statifier.Datamodel.put_in_path(datamodel, ["user", "name"], "John")
-      {:ok, %{"user" => %{"name" => "John"}}}
+      {:error, "Cannot assign to nested path: 'user' does not exist"}
 
       iex> datamodel = %{"user" => %{"age" => 30}}
       iex> Statifier.Datamodel.put_in_path(datamodel, ["user", "name"], "Jane")
diff --git a/test/statifier/datamodel_test.exs b/test/statifier/datamodel_test.exs
index 9e8041b..7f5f880 100644
--- a/test/statifier/datamodel_test.exs
+++ b/test/statifier/datamodel_test.exs
@@ -10,6 +10,8 @@ defmodule Statifier.DatamodelTest do
     StateChart
   }
 
+  doctest Statifier.Datamodel
+
   # Helper function to initialize a state chart from XML
   defp initialize_from_xml(xml) do
     {:ok, document, _warnings} = Statifier.parse(xml)