Errors in the article:
"All basic open-water courses must include the same syllabus of diving skills, physics, physiology, etc."
They do not have the same syllabus.
Your right but the members have the same minimum standard so we can start splitting hairs.
"It was written by the Recreational Scuba Training Council"
It was written by representatives from NASDS, NAUI, PADI, SSI and YMCA before the RSTC was formed. The RSTC was formed later and now the RSTC is the group that makes changes to the minimums. OK and you are saying what exactly? This is relavant how? you are arguing the chicken or the egg but it does not really matter.
"Although only six agencies are members of RSTC, as a practical matter all have to meet the RSTC/ANSI standard in order to buy liability insurance and defend themselves from lawsuits."
NAUI is not a member and no longer meets the minimum swimming requirements, yet it has no difficulty with liability insurance. Your 100% correct
"Some agencies (IDEA, NASDS and YMCA) require a minimum number of hours of instruction, typically 24............Other agencies require that students meet performance standards, and leave the number of lecture hours and pool sessions up to the instructor."
The agencies I've studied all use performance requirements rather that strict hour requirements. and that make this statement incorrect how?
"NAUI, PDIC and YMCA require four scuba and one skin dive."
I don't know PDIC's requirements. That is correct for YMCA, but NAUI requires either 5 SCUBA or 4 SCUBA and 1 skin dive. OK we have already established NAUI is not a member of RSTC Besides how is referencing NAUI incorrect here, we establishe they can all go beyond the requirements and in practice most NAUI instructors opt for the 4+1 format. But you did proove you vast understanding of the standards.
"Of course, individual instructors can exceed an agency's minimum standards, and many do."
This is misleading. Instructors from some agencies (YMCA & NAUI are examples) can require additional material while instructors from other agencies (PADI is an example) can offer, but cannot require additional material. I agree totally but in context there was nothing wrong with the statement.
Yes, it's full of errors. What's left out of the article is even more misleading than the errors included.