I was re-adjusting the canti brakes on my Nashbar Steel CX bike and pulled on the left (front) 105 5800 lever, which caused a loud "pop/crack" and caused the table to "lengthen" by about a centimeter or two. The lever essentially "gave out" and let up about 1-2cm of brake cable. Not entirely sure where the extra brake cable came from. When I first heard the pop/crack, I thought I broke something in the lever but after I readjusted the brakes again (simply adjusted cable triangle slightly to deal with the extra cable length), the brakes seem to work perfectly fine.

I'm not entirely sure what happened. Where did the extra length come from? What caused the pop/crack? Is the bike fine to ride? I think it's probably some sort of ratcheting system that loosened a notch, but it also slightly worries me that pulling fairly hard on a lever can cause this. Had this happened on a downhill, it would have been GG for me.

I'm sure somebody else has had this issue, but it's difficult to search for. Googling "brake lever pop" doesn't return many useful results.

Thanks in advance!