I would naturally read ⟨aw⟩ as /oː/ (as in e.g. ⟨hawk⟩), rather than /ɑː/. The weird part is the [e] — the only thing I can suggest is that they’re one of those people who raise /æ/ to [e] in some positions.
This whole thread is a comedy of errors stemming from different English pronunciation variants. The author of the original article evidently has the full Mary/marry/merry merger but maintains the cot/caught distinction, so "keh·ruh·kaw·ruhm" seems like a natural way of spelling the pronunciation. GP has the cot/caught merger but does not merge Mary/marry, so they read "keh·ruh·kaw·ruhm" as [kerəkɑːrəm] and understood this as distinct from Wikipedia's kær- pronunciation. And you don't have the cot/caught merger or the Mary/marry merger.