This issue is crystal clear, IF we understand how accounting works.

Discounts are not a taxable benefit unless their value is less than their book value to the company minus depreciation.

If the asset is perishable, and it is fully depreciated at the time of consumption it is not a taxable benefit.

A burger, for example, is fully depreciated by end of day. And therefore an employee eating it has no taxable benefit - as it would go in the garbage - proving it has zero value.

However, an employee getting a boat for free, the boat almost certainly has a book value to the employer.

For a boat manufacturer, it is the cost value of making it from raw materials, for everyone else it is the retail purchase value - regardless it is the book value - minus any depreciation on the asset.

If the burger maker gave the fully depreciated asset, it is not a taxable benefit. 
If they gave away a $100 gift card to be used to buy burgers, the transaction value is $100, as there is a $100 liability.