We eventually were able to unstick the ball from the rubber hoop (which somehow came unattached from the ZED part of the table) but the tube remained on the playing field. I declared broken table strats, which included ricocheting the ball from the tube into the ramp above, as seen by the purple dotted line in the diagram above. In a stunning move, I somehow managed to do this twice but didn't film either instance. (My partner is an eyewitness, though her relationship to me makes her unreliable.)
played Led Zep at my own arcade a couple of weeks ago, and after hitting that ring particularly hard, i saw a general-illumination LED bulb pop out of that same spot of the table! thankfully, there was an attendant on hand that i could call over and alert to the problem.
after talking to the arcade owner about the incident, i learned that it was the second time it had happened to that game! not sure if we've had the rubber ring itself break, though.
(the second photo is an older one, from 2021, showing that rubber ring & the intact LED.)
it occured to me then that this ring, along with that bulb, are doomed to face a lot of abuse, since it blocks off the high-payoff "Side Shot" of the game. this shot is very difficult, with a narrow entrance and a dangerous return path for balls rolling down the wall above the "LED" targets; in return, making the shot will award significantly more points compared to other shots. the only (reasonable) way to get a ball through it is with the upper flipper, and it's pretty easy to simply miss the shot high, making the ball hit the ring at full force.
no wonder that this area is getting smashed to hell so badly that rubber rings are snapping and lights are popping out of their sockets. truly the defining features of modern pinball.
PS - clearly, this table looks a bit different! my local arcade's Led Zeppelin is a Premium model, whereas OP's location has a Pro model. the Premium version replaces the "Hermit Target" at the end of the Side Shot lane with a very tight 180-degree "Scoop Ramp." the ramp leads to a bespoke wire path, which safely leads the ball onto the Right Ramp's return pathway. (compare that to having to deal with a nasty sideways-flying rebound ball after successfully completing the Side Shot on the Pro version.)
i think this incentivizes players - certainly myself included - to send the ball into that shot as hard as they can, every time. certainly, weak shots that would just barely register at the Hermit Target on the Pro would have no hope of getting up and around the Scoop Ramp, and as such, i wouldn't bother trying to send the ball in that direction at low speed on the Premium. maybe that's making the problem worse...