This was my first expert case, beginning shortly after I left IBM. It was a patent infringement case concerning real-time spectroscopic optical sensors for precision agriculture, i.e. finding the condition of each plant or small region of a field, and applying just the right amount of fertilizer or pesticide. Precision agriculture is a win all round; it improves crop yields, prevents the spread of pests, while reducing the cost of chemicals and minimizing the runoff of those chemicals into waterways and ground water.
The technology was relatively simple: LEDs and photodetectors with filters, followed by amplifiers, filters, digitizers, and a bunch of software. The defendant was a garage startup whose sensors worked, and the plaintiff was a larger company whose sensors (I'm told) did not work nearly so well. The defendant was not in fact infringing, but would probably have run out of money and so lost by default, except that their distributor (a larger company than either of the sensor outfits) went to bat for them, so the process could continue till the truth came out.
I was retained as testifying expert for the defense, and prepared reports on noninfringement and invalidity. The case settled very favourably in 2009, shortly before my scheduled deposition. A good first outing, for sure.