I suspect your friend's friend was probably mistaken, or saw a "Very good copy." Cartier makes a lot of money with LOVE bracelets. I believe the figure I saw about 4-5 years ago was something like $35 Million per year. Cartier offers a hand full of things in sterling silver(cufflinks, lighters, baby rattles), but I can't imagine them releasing the Love bracelet in sterling silver. Its always been made of gold or platinum.
I doubt Cartier would do one in sterling as it might make people say why spend for it in white gold or platinum. Sure it would allow them to sell in greater volume, but that may take away from the perceived exclusivity of the brand. I know some people that stopped buying Tiffany products when they went crazy offering sterling silver products in the 1990s. They felt it diluted the brand, and what was the point of having things that high school kids in fancy neighborhoods are wearing.
"They felt it diluted the brand, and what was the point of having things that high school kids in fancy neighborhoods are wearing." Love that! Of course, my son's girlfriend wears one of her mom's Love bracelet (her mom has 3), but she's def the exception to the rule.