--- before/addons/core/Scripts/Game/ERR/00_Core/ERR_ObserverPlayerView.c
+++ after/addons/core/Scripts/Game/ERR/00_Core/ERR_ObserverPlayerView.c
@@ -2,6 +2,20 @@
 // spectators of that body. No client-supplied position affects gameplay.
 class ERR_ObserverViewRules
 {
+ // The body and camera arrive through independently timed replication streams.
+ // Keep the sampled world axes and world-axis eye offset together. Applying
+ // the proxy body's rotation to delayed body-local aim adds its yaw error to
+ // both aim and eye position, even when the owner's camera is steady.
+ static void Encode(vector body[4], vector view[4], out vector pose[4])
+ {
+  for (int axis = 0; axis < 3; axis++) pose[axis] = view[axis];
+  pose[3] = view[3] - body[3];
+ }
+ static void Decode(vector body[4], vector pose[4], out vector view[4])
+ {
+  for (int axis = 0; axis < 3; axis++) view[axis] = pose[axis];
+  view[3] = body[3] + pose[3];
+ }
  static bool Sample(vector position, vector forward, vector up, float fov, float nearPlane)
  {
   // Negated bounded comparisons also reject NaN/infinity before matrix math.
@@ -105,13 +119,13 @@
   float now = GetGame().GetWorld().GetWorldTime();
   if (now - m_ERRViewRequestAt >= 500)
   { m_ERRViewRequestAt = now; Rpc(ERR_RequestPlayerView); }
-  vector local[4], world[4];
-  if (!m_ERRViewBuffer.Read(m_ERRObservedId, now, seconds, local, fov, nearPlane)) return false;
+  vector pose[4], world[4];
+  if (!m_ERRViewBuffer.Read(m_ERRObservedId, now, seconds, pose, fov, nearPlane)) return false;
   RplId scopeWeapon; vector scopeData;
   m_ERRViewBuffer.Scope(scopeWeapon, scopeData);
   if (scopeWeapon != RplId.Invalid() && !ERR_ObserverScope.Resolve(target, scopeWeapon, scopeData)) return false;
   target.GetWorldTransform(world);
-  Math3D.MatrixMultiply4(world, local, transform);
+  ERR_ObserverViewRules.Decode(world, pose, transform);
   return true;
  }
  [RplRpc(RplChannel.Reliable, RplRcver.Server)]
@@ -157,15 +171,15 @@
   PlayerCamera camera = GetPlayerCamera();
   CameraManager manager = GetGame().GetCameraManager();
   if (!mode || !mode.Active() || !ERR_Actors.CanFight(actor) || !camera || !manager || manager.CurrentCamera() != camera) return;
-  vector world[4], view[4], local[4];
+  vector world[4], view[4], pose[4];
   actor.GetWorldTransform(world);
   camera.GetWorldCameraTransform(view);
   float fov = camera.GetVerticalFOV(), nearPlane = camera.GetNearPlane();
   RplId scopeWeapon; vector scopeData;
   ERR_ObserverScope.Sample(actor, view, fov, scopeWeapon, scopeData);
-  Math3D.MatrixInvMultiply4(world, view, local);
-  if (!ERR_ObserverViewRules.Sample(local[3], local[2], local[1], fov, nearPlane)) return;
-  Rpc(ERR_SubmitPlayerView, ++m_ERRViewSequence, local[3], local[2], local[1], fov, nearPlane, scopeWeapon, scopeData);
+  ERR_ObserverViewRules.Encode(world, view, pose);
+  if (!ERR_ObserverViewRules.Sample(pose[3], pose[2], pose[1], fov, nearPlane)) return;
+  Rpc(ERR_SubmitPlayerView, ++m_ERRViewSequence, pose[3], pose[2], pose[1], fov, nearPlane, scopeWeapon, scopeData);
  }
  [RplRpc(RplChannel.Unreliable, RplRcver.Server)]
  protected void ERR_SubmitPlayerView(int sequence, vector position, vector forward, vector up, float fov, float nearPlane, RplId scopeWeapon, vector scopeData)