You don't know how he is playing the game... for example one way to crash the game is if you are doing a crafting build, mass manufacture items for sale, and attempt to sell them all at once, the game has a massive memory leak on the inventory screen that seemly is combinatorial too (seemly it reloads the inventory screen whenever you sell a item, and keeps the old inventory memory alongside the reloaded, so the increase is faster than linear), when it runs out of RAM it crashes.