In a 'storyfag' RPG, such as Torment: Tides of Numenera, suspension of disbelief is an important feature. Asking someone 'who are you?' two or more times with the same answer each time should not be possible, as it inevitably breaks the suspension of disbelief. There are two options which don't: one is pruning the 'who are you?' branch and another is an 'What's wrong with you? You've already asked me that!' type of response (associated with a simple count variable).
No need for that. The question is how the already available dialogues with already available choices should be implemented, not the addition of new choices. There is an already constructed / written full tree as a start. But it shoudn't be static. Depending on the type of choice, either only taken branches are pruned, or the whole subtrees are pruned as well (when there is an exclusive choice). That is not too difficult to implement.
In contrast to repeating options, reload spamming is something a player does to himself to diminish the fun (unless the player is an assburger and finds pleasure in performing exhaustive search).
Reload spamming to get the desired outcome can discouraged by good design (where the degrees of success / failure are different from binary, feedback is not always immediate, and there are 'more ways to skin a cat', i.e. failure can lead to opening alternative opportunities). If the player load spams under those circumstances, that's his choice.
