Why did tiktaliktak fail to notice the ice splitting?

Tiktaliktak likely failed to notice the ice splitting due to a combination of environmental distractions and possible sensory limitations. The sound of the ice cracking may have been masked by other ambient noises, or Tiktaliktak may have been focused on other activities, leading to a lack of awareness. Additionally, factors such as visibility conditions or the gradual nature of the split could have contributed to the oversight.