Handbrake should be used to keep it effective (so that the cable moves regularly and does not get stuck). And, if the gear is released accidentally, you still have the brake, and vice versa.
(Myself, I have always parked with handbrake on + gear in 1st or reverse; nowadays with my VW it's pretty automatic because it's DSG and you have to put the selector to P to take the key out, and electric parking brake activates automatically.)
> (unless on grade) to avoid the handbrake becoming less
> effective over time as the cable stretches.
Your justification for not using the handbrake for its intended purpose it that it may become less effective in the future? Seems counter intuitive unless I'm missing something...
If you believe your handbrake cable will stretch/break, just check it regularly. It really isn't that expensive to replace (compared to other car maintenance) and there's no harm in being extra cautious in this case.
The only emergency it is useful for is when you really have to pull a 180 right now and tight, as the automated systems do not expect this situation and will relax the brakes while you're deliberately trying to spin. I wouldn't trust even an above average drive with pulling that off - it's not being practiced. Usually it would be a desperation move when there's no space and a head on collision is likely.
So was it in gear or was it in neutral?
this happened in my 2005 mazda 3 and the habit carried over to my 2017 Golf (not sure if the brake design is similar or not, maybe it's not necessary on the vw)