43K with unexpected shoe issues

This is how my Salomon XT Wings look like after I've run 400K with them. They are in fine condition, except for one thing. Can you guess what it is? 

One of those (bleep) shoelaces snapped today after 6K. I'm kind of happy that it happened now and not during next weeks Zermatt Marathon. I tied the loose ends together, but there was no way to fix them properly. Luckily I was able to continue, as there was a long way to go.

By the way, exactly the same thing happened to my previous XT Wings after 900K. I'm not sure what's going on here. I'm not wearing them extra tight or anything like. Actually I prefer to err on the loose side.

The rest of the run was awesome. The weather was fabulous with some sun and cool temperatures around +15C (60F). At 22K point I went home to eat and taped my left ankle once again. 

I ran 43.1K (26.8 miles) in 5:31. This was my 26th ultramarathon of the year and there's 26 more to run before we call it a year.