I'm not sure how non-leading yes/no questions would screw things up, assuming you knew the answer to the yes/no question ahead of time. (And if you don't, then the leading question might actually be worse, in my non-lawyer opinion.) To use your example, I don't see a significant difference (under cross-examination) between the two questions:

>So not “Did you check the victim’s pulse?” but “You didn’t check the victim’s pulse, did you?”

Again, I recognize that you know more than I do and have vastly more experience in the court than I do*, so I admit ahead of time that I might be missing something.

*My experience is limited to unsuccessfully fighting a traffic ticket when I was a young adult and serving on two juries.

IANAL, but I'm assuming that while you're not allowed to ask leading questions during direct examination, you are allowed to not ask leading questions during cross-examination. If I'm understanding u/thisissuchbsffs correctly, I think that's what she was referring to.