If the safety was on and the rifle was in a truck and collecting dust then of course a situation might arise that as the safety is let off then the sear and trigger do not align properly and then BANG. However, I think the likely cause of the problem is that the Wby Mark V is extremely easy to adjust for sear engagement. In addition, before all factory rifles were fitted with trigger return springs that would do justice to the front end of a Mack truck, the Wby was also very easy to adjust to a very light trigger return spring tension. In short, greatly reduce the sear engagement and also have a very light trigger return spring and then some dust collect.....then the sear might not engage as the safety is lett off. A Wby can be ajusted for both spring tension and sear enagement without taking the rifle apart.

Having said that, if the Wby is set for lots of sear engagement and heavy trigger return spring tension then I can't see any reason why the rifle would fire when the safety is let off.

Perhaps the real problem is that the Wby Mark V offers too much choice to the shooter in terms of trigger adjustment

Mike