Had a scope that fail during a hunt. It was a coues wt hunt, missed getting a nice animal. Switched to another rifle for the remainder of the hunt. Luckily brought along a backup.
Another scope failed a week or so before another coues wt hunt.
Had many Leupold scopes fail since 1983 when I began hunting. Many failed randomly when attempting to move the POI at the range. In all cases the cause was a broken erector. It took me a while to realize Leupold scopes had an issue.
One time I talked to a tech at Leupold. He suggested I turn the turrets lock to lock several times to distribute the grease. While it worked, I lost trust in that scope. I sold it soon thereafter.
Eventually I sold off all my Leupolds except a 2.5 compact which is on a 22RF. When considering the difficulty of being drawn and the cost of a hunt, life is too short to trust a Leupold especially if you are a turret twister. IMO at some point it will fail.