Introverts act distant in the beginning because they tend to over love. Over give. Over care. And before they go all nuts for you, they want to be sure. Observe you from a distance. Watch your actions. Read your energy. They want to give, they're just making sure it's worth it.
Introverts don't argue, they go silent. They understand, they forgive, they give you chances after chances. But once they're done, it's over. They won't ask you for an explanation. They won't tell you their reasons. And they absolutely won't chase you. Take it or leave it.