I think you did everything you could in an awkward situation. I'm glad he was nice and didn't get mad at you!
If it helps, I also had a mortifying situation on Saturday, so I'll share too! Not quite as bad though.
I was shopping in a homeware store, and looking at some baking trays. Next to me a shop assistant was standing talking to a couple who sounded like mad keen bakers/chefs based on what type of products etc they were discussing (not eavesdropping but it was hard not to overhear). The female customer was crouched down with her back to me looking through some items, while her male companion was standing opposite facing me as the three conversed. I had taken some trays off the shelf to look at, decided they weren't suitable, and put them back on the shelf - exactly where I'd gotten them from. Unfortunately for me, it turns out that they'd actually been on the edge
of a shelf e.g. hanging off the edge so were only half supported.
So as I placed them onto the shelf, the pile of heavy baking trays fell off the shelf and onto the head of the other customer!
I tried to grab them but wasn't fast enough. This poor lady had a pile of trays rain down onto her head without warning (remember her back was to me!) as myself, the male customer and shop assistant scrambled to grab them. I was terrified she'd been hurt but fortunately it was no harm done. Her partner ended up making a joke to lighten the situation and we all moved on after extensive apologising on my part, and the shop assistant decided those trays would be better stored on the bottom shelf. They were heavy
trays, and although I had no way of knowing they'd been put in a terrible location, I felt quite guilty about it. Thank goodness they were nice!! (Just to note, I hadn't reached over the ladies head to get the trays, I was standing in front of the shelf, but the edge they were hanging off was towards her meaning when they fell they fell directly onto her even though I hadn't reached over her head). Ick. These things just happen sometimes, all we can hope for is that people are understanding.