If I understood your thread, your client's domain was "shut down" because they received a report that its WHOIS details aren't updated.
FYI, all registrars must ensure all domains registered with them must have complete and accurate WHOIS details. This is one of their agreements with ICANN.
If they receive a report from either ICANN or a 3rd party that a domain's WHOIS details aren't updated, the registrar will use all available resources to notify the domain's registrant and contacts. If no one responds, the registrar will shut down the domain to hopefully get their attention.
And it worked, in this case. Just do what the registrar said and they'll restore access to the domain soon.
Unfortunately it doesn't matter what registrar you use. All will send periodic notices to their customers reminding them to ensure their domains' WHOIS details are updated.
Your client is actually lucky. One registrar I know will charge $9.95 if the domains' details aren't completely updated on time, and all registrar will eventually delete the domain if no one responds despite the website being shut down.
If you're looking for someone to blame, blame the higher authority who's forced this on the registrars. Or even your client who didn't proactively update his/her domain on time, although it's understandable if s/he didn't know this thing anyway.