Never (knowingly) had liability insurance while I was instructor. Crossed fingers and hoped for best. Looks like I got away with it, given I no longer instruct, ... unless of course some disgruntled ex-student comes after me in 20 years time saying from his hospital bed that I taught PFLs badly !
Hmm .. how does one cover oneself against that little scenario then ? Pay for further liability insurance each year in perpetuity ?