Well, it finally happened, and I'm surprised that after so much fact-checking, 18 months in print, and so many copies sold that it took so long. A colleague in our Portland office found a one-sentence substantive error on page 77 regarding the "File-and-Suspend" Social Security strategy. Somehow that sentence survived our fact checking and I had forgotten that it was still in the manuscript.
I discussed how John, age 66 could file and suspend his benefit, and his spouse Mary could collect a higher spousal benefit based on John's higher earnings. Then when John turned 70, he could claim his much higher benefit and Mary could continue to receive the spousal benefit which was higher than if she had filed on her own (lower) earnings record. That part is still correct and is a valid strategy, although there is talk in Washington of closing that strategy down. (So far, it's only talk and nothing more.)
The error is when I stated that while John was suspending his benefits he could receive a spousal benefit on Mary's account. That is not true. If one spouse is suspending a benefit he/she cannot take a spousal benefit at the same time. Here's more info on it directly from SocialSecurity.gov.
Hopefully readers thinking of using this strategy followed my advice in the next paragraph to seek competent advice first.