Can a hairy gallbladder wall cause sepsis?

Yes, but it is very unlikely. Most patients will not develop sepsis if they are treated aggressively and maintain immunity.
In a few cases of acute attacks of cholecystitis, severe grossness of the gallbladder wall, such as delayed treatment, or more serious purulent cholecystitis and gallbladder perforation, can cause inflammation of the liver, bile duct and surrounding peritoneum, and when the infection is aggravated the pathogenic bacteria can easily enter the blood circulation through the bile duct and cause sepsis, which can cause functional damage to multiple organs.