The tip breaks on the knives pictures are very easy to do as they are thin and stainless steel. I sharpen knives for friends and family, and such tip failures are very common with carpenters and similar craftsmens. You can easily regrind the points, or just convert them to blunt screwdriver tips or chisels as that is how they are frequently used. Those people don't tend to view the knives as pure cutting tools, but more as multi-tools. They generally don't look at the knives as having failed when the tip cracks (depending on what was being done), it is just the expected scars from the job, just the same as they tend to have on their hands.
The edge damage on the top buck is decently hard to do, you would need to be trying to chisel cut through a piece of hardened metal and hitting the knife with a hammer. It only went to the extent that it did because of the hollow grind, the damage would not be nearly as extensive on a flat ground blade and then would tend to be just limited to the edge bevel. Note Buck actually used to promote their knives by doing exactly this with them - cutting heavy bolts so their warrenty department should be careful not to be hypocritical about usage.
In regards to warrenties, all that matters is did the knife act as promoted and expected. Was the break the expected behavior of the knife, and was this behavior clear from the way in which the knife was promoted? In most cases a warrenty department will allow a lot of grace and do more than it legally has to because the cost of replacements is no where near the sticker price you see and such warrenty service tends to make a lasting impression on the buyer.
-Cliff