Lightning can be a tricky matter. Indeed you need to be very careful when around all storms, not just the most intense ones. It's also true that some storms spit out much more lighting than others, and some like to spit out loud, nasty CGs in that perfect area to view tornadoes (from the south and east of the updraft). Every situation is a little different, so you need to always be aware of where lightning seems to be preferred in a storm. Unfortunately, taking the ultimate precautions against such close calls generally will force you to abandon good vantage points or call off the chase altogether. And you don't wanna do that, do you?
It seems general points about minimizing your chances of being struck by lightning while chasing include:
-stick to environments that contain tall objects like trees, power poles, wind turbines, or high-tension high-voltage lines. You don't want to be the tallest object nearby. A place like W Texas is pretty bad to be in a highly electrical storm.
-Get as low as possible. Even if you are one of the taller objects around, if you can get low, your chances of being struck should go down. Ways to get low include crouching or looking for low spots in culverts, ditches, ravines that run near roads, for example.
-Make yourself an unattractive target: if you carry around a lot of metallic objects like cameras, tripods, or instrumentation, you're increasing your odds of a bolt hitting you as opposed to some other nearby target. Wear rubber/plastic shoes, too.
-Stay inside a car when possible. When in a car, keep all doors closed and windows up all the way. While a car does act like a cage to direct electricity around you and to the ground, you can enable current to enter if you leave any openings. This also means you need to unplug all electrical devices wired to the battery or an inverter (like computers, cameras, GPS, cell phones, inverters) and keep your hands away from objects that protrude outside the car or have a path to a ground outside the car. These mainly include the radio and instrument cluster devices. If the pedals are coated with metal, also be careful not to sit your feet on them.
I have had one or two close calls with lightning strikes while I was out in the open. Unfortunately, even when keeping your head on a swivel, lightning gives essentially no warning (those one or two sections before it strikes won't be enough in many cases to avoid getting struck), and so it is generally impossible to avoid on such short notice. The best you can do is take the preventative steps I listed above and be prepared in the event you or someone nearby is struck. Remind yourself every time you get close to a storm about the lightning hazard. Situational awareness is key.