SQLAlchemy can be made verbosely echo all SQL statements it executes. This way you can replay issues in a ws-db-shell by hand and manually inspect the state of the database and transaction between each SQL statement.
Do the following to turn on the logging.
Edit development.ini and set echo variable for your connection:
[app:main] # ... sqlalchemy.url = # ... sqlalchemy.echo = true
In the same file, add a section to make SQLAlchemy logging verbose:
[logger_sqlalchemy] level = DEBUG handlers = qualname = sqlalchemy