As someone who has been quite close to the machine for the last 5 years I can say that HC and 212man are correct. There are two facts in play that can confuse:
Fact 1. The aircraft is certified to JAR29 amdt 47. The TCDS confirms this.
As such Sikorsky had to satisfy the FAA that it complied with FAR 29.927. They did this by persuading the regulators that the only possible cause of loss of lubrication was an oil leak somewhere in the oil cooler line and hardware, hence the inclusion of the shutoff valve.
Fact 2. The aircraft has NO 30 minute MGB run dry capability. The salesmen can get clever and imply it by virtue of Fact 1!!!
When the MGB was first tested against FAR 29.927 Sikorsky were confident that the gearbox would pass the run dry test, why not be - the S70 gearbox is OK. However it did not run for 30 minutes (I could quote a figure as to how long it did run but to do so might be dangerous in light of the Cougar accident?), hence the "bolt on" oil cooler shut off valve - and it does look like a bolt on! This is also why, I believe, selection of the valve is not yet automated. The valve was so last minute that there was no time available to get clever with it!
So Brian, the aircraft is "compliant" with the "run dry" certification clause, but only because of a pretty big fudge factor that the regulators bought. Bottom line is that MGB does not have a certified 30 minutes operating capability without any MGB oil circulating.
HTH?