If I believe that I've found an error in Timatic---for example, it claims that a particular document is not required, but I believe that the document is required under applicable laws and regulations---is there any way to ask them to consider making a correction?
There is a contact page on the Timatic web 2 website:
Do you experience any technical problem, have any invoicing questions, content related issues or need more information about your subscription status?
Please contact our Customer Service via www.iata.org/cs
On the IATA website, it looks like you need to use the Customer Portal:
The IATA Customer Portal is packed with useful services, product information, useful tips and tricks specially tailored to you. You can use it to contact our Customer Service Team easily, including live chat or directly purchase from our online store.
You can create an account here.
It is preferred to have solid evidence to back it up (preferably an e-mail from the actual border authority)