Recipe? It's just a guideline, right?

Spending a little time at Lark Creek Blue, I find they've allowed one of the drinks we created, Blood and Flowers, to drift from what it had been.
The drink has been very popular--it's got just the right balance of dangerous exoticism and understandable comfort. We infuse tequila with hibiscus flowers (jamaica) and chipotle peppers, then mix it with blood orange grenadine and fresh lime juice.
What tipped me off to the "drift" was the color of the drink. If there is one thing jamaica does well, it is provide color. The original Blood and Flowers was a stunning shade of magenta, opaque, intense--ready to stain anything you spilled it on. What I saw going out of the bar was pallid and wan--not the gutsy drink we built.
So what went wrong? As I started to ask around, everyone insisted they followed the recipe. And I believe they did, to a point. But recipes are collections of ingredients and methodology--what I came to understand is that the bar staff focused on the ingredients but neglected the methodology. Specifically, they used the right amount of jamaica, but steeped it for less than the 3 hours called for, and that made the drink completely different.
It's that collection of little details that make up the entire recipe, and often you can skimp a little, or adjust, but not all the time.