Is H. P. Grice's 'objector' in "Causal theory" modelled on Austin?

Grice argues that the doubt-or-denial condition attaching to L-statements ("look"-statements) is a conversational implicature, so L-statements have truth-conditions that are not affected by the doubt-or-denial condition, and so we can talk meaningfully about how things look to us even if it sounds odd.

Grice’s "objector" — who seems at least inspired by J. L. Austin, if not modelled on him — argues that Lstatements without the doubt-or-denial condition are neither true nor false, but Grice replies that this objector confuses implicature with presupposition.