I suggest that you either replace the curly braces with parentheses, or use 'or' rather than '||':

  $query->execute() || ($SQL_FAIL =1);
  $query->execute() or $SQL_FAIL =1;
[download]

'or' has a lower precedence than '=', but '||' has a higher precedence, which is what makes parentheses necessary in your original statement.