diff --git a/backend/src/services/dataset_review/repositories/__tests__/test_session_repository.py b/backend/src/services/dataset_review/repositories/__tests__/test_session_repository.py
index 9ac49b13..77d968ea 100644
--- a/backend/src/services/dataset_review/repositories/__tests__/test_session_repository.py
+++ b/backend/src/services/dataset_review/repositories/__tests__/test_session_repository.py
@@ -14,7 +14,9 @@ from src.models.dataset_review import (
     FindingArea,
     FindingSeverity,
     ReadinessState,
-    RecommendedAction
+    RecommendedAction,
+    SessionCollaborator,
+    SessionCollaboratorRole
 )
 from src.services.dataset_review.repositories.session_repository import DatasetReviewSessionRepository
 
@@ -75,6 +77,32 @@ def test_load_session_detail_ownership(db_session):
     loaded_wrong = repo.load_session_detail(session.session_id, "wrong_user")
     assert loaded_wrong is None
 
+def test_load_session_detail_collaborator(db_session):
+    # @PURPOSE: Verify collaborator access in detail loading.
+    repo = DatasetReviewSessionRepository(db_session)
+    session = DatasetReviewSession(
+        user_id="user1", environment_id="env1", source_kind="superset_link",
+        source_input="http://link", dataset_ref="dataset1"
+    )
+    repo.create_session(session)
+    
+    # Add collaborator
+    collab_user = User(id="collab1", username="collab", email="c@e.com", password_hash="p")
+    db_session.add(collab_user)
+    
+    collaborator = SessionCollaborator(
+        session_id=session.session_id,
+        user_id="collab1",
+        role=SessionCollaboratorRole.REVIEWER
+    )
+    db_session.add(collaborator)
+    db_session.commit()
+    
+    # Collaborator access
+    loaded = repo.load_session_detail(session.session_id, "collab1")
+    assert loaded is not None
+    assert loaded.session_id == session.session_id
+
 def test_save_preview_marks_stale(db_session):
     # @PURPOSE: Verify that saving a new preview marks old ones as stale.
     repo = DatasetReviewSessionRepository(db_session)
@@ -127,6 +155,23 @@ def test_save_profile_and_findings(db_session):
     assert updated_session.profile.dataset_name == "Test DS"
     assert len(updated_session.findings) == 1
     assert updated_session.findings[0].code == "ERR1"
+    
+    # Verify removal of old findings
+    new_finding = ValidationFinding(
+        session_id=session.session_id,
+        area=FindingArea.DATASET_PROFILE,
+        severity=FindingSeverity.WARNING,
+        code="WARN1",
+        title="Warning",
+        message="Something"
+    )
+    
+    repo.save_profile_and_findings(session.session_id, "user1", profile, [new_finding])
+    
+    db_session.expire_all()
+    final_session = repo.load_session_detail(session.session_id, "user1")
+    assert len(final_session.findings) == 1
+    assert final_session.findings[0].code == "WARN1"
 
 def test_save_run_context(db_session):
     # @PURPOSE: Verify saving of run context.
diff --git a/backend/src/services/dataset_review/repositories/session_repository.py b/backend/src/services/dataset_review/repositories/session_repository.py
index 35116c56..74b7af14 100644
--- a/backend/src/services/dataset_review/repositories/session_repository.py
+++ b/backend/src/services/dataset_review/repositories/session_repository.py
@@ -10,13 +10,15 @@
 # @POST: session aggregate reads are structurally consistent and writes preserve ownership and version semantics.
 
 from typing import Optional, List
+from sqlalchemy import or_
 from sqlalchemy.orm import Session, joinedload
 from src.models.dataset_review import (
     DatasetReviewSession,
     DatasetProfile,
     ValidationFinding,
     CompiledPreview,
-    DatasetRunContext
+    DatasetRunContext,
+    SessionCollaborator
 )
 from src.core.logger import belief_scope
 
@@ -44,8 +46,9 @@ class DatasetReviewSessionRepository:
         @PRE: user_id must match session owner or authorized collaborator.
         """
         with belief_scope("DatasetReviewSessionRepository.load_session_detail"):
-            # Note: We check user_id to enforce the ownership_scope invariant.
+            # Check if user is owner or collaborator
             return self.db.query(DatasetReviewSession)\
+                .outerjoin(SessionCollaborator, DatasetReviewSession.session_id == SessionCollaborator.session_id)\
                 .options(
                     joinedload(DatasetReviewSession.profile),
                     joinedload(DatasetReviewSession.findings),
@@ -60,7 +63,12 @@ class DatasetReviewSessionRepository:
                     joinedload(DatasetReviewSession.run_contexts)
                 )\
                 .filter(DatasetReviewSession.session_id == session_id)\
-                .filter(DatasetReviewSession.user_id == user_id)\
+                .filter(
+                    or_(
+                        DatasetReviewSession.user_id == user_id,
+                        SessionCollaborator.user_id == user_id
+                    )
+                )\
                 .first()
 
     def save_profile_and_findings(self, session_id: str, user_id: str, profile: DatasetProfile, findings: List[ValidationFinding]) -> DatasetReviewSession:
@@ -77,12 +85,21 @@ class DatasetReviewSessionRepository:
                 raise ValueError("Session not found or access denied")
 
             if profile:
+                # Ensure we update existing profile by session_id if it exists
+                existing_profile = self.db.query(DatasetProfile).filter_by(session_id=session_id).first()
+                if existing_profile:
+                    profile.profile_id = existing_profile.profile_id
                 self.db.merge(profile)
             
-            # For findings, we might want to sync them (remove old ones if not in new list, or update)
-            # Simplest for now: add/merge findings
+            # Remove old findings for this session to avoid stale data
+            self.db.query(ValidationFinding).filter(
+                ValidationFinding.session_id == session_id
+            ).delete()
+            
+            # Add new findings
             for finding in findings:
-                self.db.merge(finding)
+                finding.session_id = session_id
+                self.db.add(finding)
                 
             self.db.commit()
             return self.load_session_detail(session_id, user_id)