Dude had to impress the girl... I would have done the same
Looks like the missing link way is the simplest and safest. Personally never used the pin since the invention of those missing links back like in 1986 maybe when shimano came up with them. Believe it or not I still have that 1st link I ever saw in my chains stuff tiny plastic bin. This one came in a 105sc group my dad got me in a trip to Japan, the group was just getting in the market.
Shimano used to make stuff, tried them in the lower groups and then rolled them over up to the more fancy groups because after 105sc the ultegra group showed up a few weeks later with the same improvements.