In the _logintoboggan_process_validation() function, it calls user_module_invoke('update', ...) so that other modules can react to the user having been validated. I've got a custom module, that controls a users registration to a mailing list. I've got a hook_user that checks for 'after_update' because it needs to also catch changes to $account->language. Users should only be on the mailing list if they are validated.
Anyway, to make a long story short, logintoboggan only fires 'update' and not 'after_update' so my code doesn't happen. Of course, I can put in a bunch of hacks (like $account->language = $edit['language']) so that I can do my mailing list updates in 'update', but I really think that logintoboggan should call 'after_update' as well as 'update'. Other modules which depend on 'after_update' to react to user changes will also be broken.
Here is a very small patch that makes this change.