I suspect he means that in some jurisdictions, you need to be a licensed medical practitioner of some sort, so the traditional "on the ground" experience of midwives by itself won't qualify.
This could be a translation error, but "birth nurses" seem to be called "midwives" in the UK whereas that's not the case in the US (at least as I understand it).
There are different certifications. One in the US is Certified Nurse Midwife, essentially they are RNs with a certification in midwifery as well. They can have privileges at hospitals, which is a very useful backup in cases where something goes wrong in a non-911 sort of manner. There are also Certified Midwifes, which have a somewhat less medical oriented training and may not be able to bring patients into a hospital as 'their patient'.
(A little late but...) I said that because, for example I stubbled across a UK show called 'Midwives' and it was about a maternity ward. Most of the people there are what I would call 'nurses' in the US, even if they are Nurse-Midwives by certification. I was expecting the show to be about something more akin to home-births.
I have an aunt that's a neo-natal nurse, and I've never heard her refer to fellow nurses as midwives (but I've never directly asked her before).
for a bit of insight into the US legal situation.