such an assumption is not strong enough to guarantee that Ps has a 50-50 coinflip hypothesis.
What do you mean by 50-50 hypothesis? Is it E1/2 such that ∀n:P(Thn|E1/2)=P(Ttn|E1/2)=1/2? If that’s the case, it doesn’t seem fair to ask from a student to have such hypothesis: the task is to learn to imitate teacher, and teacher doesn’t actually perform behavior like HTHHT, it can be either perform either HHHHH or TTTTTT.
What do you mean by 50-50 hypothesis? Is it E1/2 such that ∀n:P(Thn|E1/2)=P(Ttn|E1/2)=1/2? If that’s the case, it doesn’t seem fair to ask from a student to have such hypothesis: the task is to learn to imitate teacher, and teacher doesn’t actually perform behavior like HTHHT, it can be either perform either HHHHH or TTTTTT.