Nitpicking about a W-9 or W-10 form does not change the bottom line. If the provider refuses to provide his or her tax information, you write "refused" in the SSN box for the credit, and attach a written statement the gives as much identifying information about the provider as you can, and also describes the efforts you made to get the number. The IRS will then investigate the provider, possibly audit them, and definitely assess tax plus a penalty to the provider for failing to report and pay tax on the income. If you don't want the IRS to tax and penalize the friend, then you can't claim the credit. (For this reason, friends who provide child care for friends need to discuss the tax implications in advance.)
As for being "ill-informed", when you have volunteered here for 6 years and answered 10,000 questions, you might earn the right to call on of the other volunteers "ill-informed." Until then, thank you for your tax opinion but keep the personal comments to yourself.
