He mangled her vintage hymnal
Happened about three or four years ago, still comes back to make me squirm now and then. Also, sorry for the length. I hate long cringes as much as you do but I've wanted to get this tale out there for a while.
I used to work as a part of a two-person design team at a small office supply store in the copy/print centre. When our plates got too full (as they often did), smaller print jobs would sometimes be outsourced to members of the retail section of the store. One day while my superior and I were particularly backed up with work, a stern but nice-enough woman came in with a very old hymn book from her church. She had wanted to gift it to her pastor, but it was falling apart at the spine, so she wanted us to coil-bind it for her, which was a simple-enough task for anyone seasoned with the procedure. However, due to our heavy workload, a happy-go-lucky cashier from the other end of the store offered to step in and help. Altogether it would have taken 10 minutes tops to complete, but we were so backed up that even so small a time-save was greatly appreciated.
I was still pretty new to the job at this time, so the cashier, who'd been there for about a year, approached the senior designer for a run-down on the procedure (remove the original comb-binding, slightly trim the spine and subsequent tattered edge, then punch new holes into the book so that it could be re-bound with a new, sturdier coil). There's a pause, and when I look up I catch a glimpse of the last of the cashier's eagerness draining from his face as he realizes he's a bit out of his comfort-zone with this task, but since he's a trooper and really wants to help us out, he hesitantly makes his way to the bulk cutter…and cuts off a little too much. Some of the treble clefs and text in the songbook have been trimmed into. Not the end of the world, but definitely not the result any of us would have wanted.
At this point he's definitely ready to back out, but the senior designer talked him into seeing the task until the end. I didn't feel it would be appropriate to interrupt my own task list to help, but in retrospect I really should have stepped in, because it was obvious he was not feeling it anymore, and was carrying on out of sheer Herculean willpower to help us during a busy time. Very nervously, the cashier walks back out the the coil machine, which, by the way, is in plain view of the customer.
For a few minutes I got wrapped up in my work and lost track of the situation until I had to retrieve a test print from behind the counter to investigate it. The printer was situated at the far end of the counter the coil machine was stationed upon, and I noticed that the cashier is currently motionless in front of it. He turned to me, eyes wide, and showed me what he had done to the customer's book.
His first attempt to punch a row of, oh, two-dozen or so holes into the spine had missed, so that only half of every hole was visible – picture lots of little C's eating into the edge of a piece of paper, making the edge look a bit like a row of tiny, angry teeth. In an attempt to correct this he had pushed the spine of the book further into the machine and had punched it again, which worsened the situation and created little flat-bottomed figure-eights along the edge of the book, rendering it completely ruined. Again, he had done this in plain view of the customer, who now looks quite visibly angry and is standing with one elbow propped intimidatingly on the counter to have a better look of the mess he's done to her precious hymn book. I look to him, horrified, and have no idea what advice to offer. As far as I was concerned – and I was right – it was irreparable.
He glimpsed the customer, then studied the book he'd damaged hard, turned beet-red, and told the customer clearly, but with dread:
"Just a sec'…."
…and slowly made his way back to the office where the senior designer was stationed. I'm thinking, "What in the world could he possibly do at this point to salvage this lady's book?"
As it turns out he didn't actually have a plan. Instead, he lowered his forehead to the senior designer's shoulder, half-laughed and half-sobbed and moaned, "I freaking hate the copy/print centre…I'm never working back here again…please help, she's standing right there."
The senior designer glared at him, stood up, retrieved the book and calmly and professionally explained to this understandably pissed-off lady that he was very sorry, but his team had ruined her book. As a consolation he offered to trim the cashier's disaster and coil its remains for free, even though the first and last measure of each page would be quite significantly eaten into. She took her book and left.
I didn't see the cashier for the rest of the day. But I didn't blame him. The second-hand cringe I caught from him was bad enough that I wanted to crawl under my desk and disappear too.
tl;dr: Unseasoned retail person offered to help bind a lady's vintage hymn book (intended as a gift), but mangled it in plain sight of her and made the senior graphic designer tell her that it was ruined because he was too embarrassed.