Clark (2003) takes this further, arguing that external tools (including phones, computers, language, etc.) are so crucial to human cognition that we are literally cyborgs, partly constituted by technologies (Chemero & Silberstein, 2008, p. 5).The fallacy here is in thinking that something that contributes "crucially" to some sort of cognitive or behavioral success is thereby cognitive. The crux of the difference between what Rupert calls HEC and HEMC is the difference between crucial causal contributors being cognitive crucial causal contributors and non-cognitive crucial causal contributors.
Chemero, A., & Silberstein, M. (2008). After the Philosophy of Mind: Replacing Scholasticism with Science. Philosophy of Science, 75, 1-27.