Although, at times, I disagree with tikkun Simanim, this is not one of them. The yud is a weak letter that often loses its dagesh after hei hai'di'a despite the Moshe mapik rule. See, for example, hai'ladim in breishit 33:1 & 5 or, better yet, vai'daber some 200 times (and never with a dagesh). David