They send RST_STREAM, which can be done as soon as PUSH_PROMISE is received (which SHOULD [RFC2119] be sent before any data). As I understand it, the more late

They send RST_STREAM, which can be done as soon as PUSH_PROMISE is received (which SHOULD [RFC2119] be sent before any data). As I understand it, the more latent the connection the worse the behaviour (i.e., the more likely you are to receive too much data you don't need).