CCA (and Coca Cola in general) is considered a 'safe stock' and more importantly, a safe company that isn't necessarily going to be impacted by the business cycle. Hence, investors will pay a premium when investing in CCA (the higher p/e ratio).
The gross debt of a company won't give you a meaningful gauge of how the company is going, particularly for CCA. A better understanding can be gained by looking at what pricing CCA has been achieving in debt markets recently (very low spreads), and what CDS premia look like over time (also very low, and one of the lowest in the iTraxx index for Australia).
Do yourself a favour and only buy when the price goes down.
CCL Price at posting:
$12.47 Sentiment: LT Buy Disclosure: Held