Okay, so i'm not tripping on the sway bar connector adjustments :P
Interesting ball cup observation. I've only "popped" one off when I sheer a corner off my car...not exactly what I call brushing something hahaha. There are newer low friction ball ends (the gray ones) that I've been using lately (it's in the new Tamiya catalog). I believe they even cost less than the replacement black ones, thread on the turn-buckle tighter, snap on harder, and seem to be stiffer. There was talk at the Reedy Race about how the TRF guys were using the LF ball conectors with LF balls and having them pop off. I haven't found that to be the case. They worked fine and I highly recommend the LF gray ball connectors. If you do find yourself in a situation where a the ball connector pops off, I'd be more worried about what else may have broken after the impact that caused it haha.