Regex looking for return calls within ttsbegin/ttscommit

Return calls should never appear within a ttsbegin/ttscommit pair. If they do, the application may eventually complain that

I have recently had to look for such an issue in a third-party code, and this is the job I used to looks for suspecious "returns", which did find one. Please note, that with the current regex pattern, there may be false positives, but in my case it would take more time to write a perfect pattern, than to manually look through those false positives:

 static void checkSourceForReturnsInTTS(Args _args)
{
    TreeNode treeNode;
    TreeNode sourceTreeNode;   
    TreeNodeIterator it;
    ProjectNode projectNode;
    TreeNodeTraverserSource traverser;
    Source source;
   
    System.Text.RegularExpressions.MatchCollection mcReturnsInTTS;  
    int matchCount;
    int matchIdx;   
   
    str pattern = 'ttsbegin.*[^a-z0-9_]return[^a-z0-9_].*ttscommit';
    str matchString;
   
    projectNode = SysTreeNode::getPrivateProject().AOTfindChild("MyProject");
    treeNode = projectNode.loadForInspection();
  
    traverser = new TreeNodeTraverserSource(treeNode);
    while (traverser.next())
    {
        sourceTreeNode = traverser.currentNode();
       
        source = sourceTreeNode.AOTgetSource();
        source = System.Text.RegularExpressions.Regex::Replace(
            source,
            '[/][*].*[*][/]',
            '',
            System.Text.RegularExpressions.RegexOptions::Singleline);
        source = System.Text.RegularExpressions.Regex::Replace(
            source,
            '[/]{2,}.*\n',
            '');       
       
        mcReturnsInTTS = System.Text.RegularExpressions.Regex::Matches(
            strLwr(source),
            pattern,
            System.Text.RegularExpressions.RegexOptions::Singleline);
       
        matchCount = CLRInterop::getAnyTypeForObject(mcReturnsInTTS.get_Count());
        if (matchCount > 0)
        {
            info(sourceTreeNode.treeNodePath());
        }
    }   
}