Sentence 1: Keep fancying there's some one following us."

Sentence 2: I know nobody is following us.
Is this second sentence entailed by the first?

Answer: no

Sentence 1: one never knows when she may decide to end [a] friendship over some perceived slight.

Sentence 2: You never know if she'll end the friendship.
Is this second sentence entailed by the first?

Answer: yes

Sentence 1: Hanson staggered back, panting from his efforts.

Sentence 2: Hanson's legs were weak from his hard work.
Is this second sentence entailed by the first?

Answer:
it is not possible to tell