Difference in unpadded length of input_ids and label_ids

[vardaan123]

In the function convert_examples_to_features, each word may be split into >1 word by the BERT tokenizer

token = tokenizer.tokenize(word)
tokens.extend(token)

but the length of labels remains the same. So, the unpadded length of input_ids and label_ids is not the same in such cases. What is the intuition behind this? Is this a bug or done purposefully?