I always check springbars if I work on a watch, even if I haven’t needed to disturb them. I apply the ‘pass the parcel’ principle, I was the last person to touch it so any subsequent springbar failure could ( wrongly) be attributed to me.
Failed springbars in bracelet clasps are not uncommon, I often split the clasp to get at the caseback and I’ve seen springbars come apart when the tension is released.
On old watches I often fit all new springbars FOC, it’s better than the owner having his freshly serviced watch drop off his wrist!