We also tested a floating hot dog (we detached the leads from the ground wire, so it was basically the hot dog and about 3' of unattached copper wire), and it still made little sounds as it was touched to the tower. We didn't have a way to safely touch the hot dog with no extra wire attached, unfortunately.
Many tower climbers historically jumped onto AM towers (usually at lower power levels), and they still felt little shocks climbing the tower.
Even if the tower is off, if it's near any other sites, they can draw a significant amount of RF (as a good AM tower is a good AM antenna) and if it's not grounded, that RF will go through a person too!
This specific tower site doesn't require lights on the shorter towers, so it's not an issue here, but for sites with lights needing replacement, most nowadays turn off power to the tower and ground it before anyone climbs the tower.
Not to do with RF, but there are old YT videos of HV linemen who literally hop out a helicopter onto an HV transmission line to manually inspect it. As the helicopter approaches, they hold out a long pole which is bonded to the aircraft's frame to bring it to the same potential as the line. It starts arcing quite a few feet out until the potential is neutralized and the lineman can "safely" step out onto the line and start working.
I imagine this inspection work is done with camera-equipped quadcopters nowadays.
