Ionized air is conductive. It could work as metal lightning rod

It does not matter how you ionize air. In a places where lightning protection is very important, often used radioactive material in lead can with hole at top as ionizer at the top of regular lightning rod. This greatly increase "length" of conductive "wire", so catching lightnings is more effective.

Strange that in the video they used green laser. With enough power it could ionize air too, but UV laser will be much more effective. And also much cheaper, since nice UV lasers could be made using nitrogen in air as laser mediun.

Or, may be, it is just a camera reads UV light that way.

But still laser is much more complex than simple box with radioactive substance inside that does not need any power or maintenance and could work for centuries to catch the lightnings.