Originally Posted by I-Am-Zim
In Star Trek VI: The Undiscovered Country, General Chang had a Bird of Prey that could fire while cloaked. At the time, it was the only one of its kind. When Kirk asked Valeris how many of thos things were out there, she said "Just the prototype". So, technically, the Romulans could have stolen the technology from the Klingons. Hence the Scimitar's ability to fire while cloaked.
True, plus they had 75 years to improve on the design, too. Very possible.