Was the Apostle Paul a Widower?

Denny Burk makes the case. His main points are outlined below. Read the whole thing for explanation and defense.

Paul puts himself in the category of being "unmarried" in 1 Corinthians 7:8.
The word "unmarried" translates the Greek word agamos.
Paul uses the term agamos to refer to those who have been married but now are no longer married.
The context of agamos in 1 Corinthians 7:8 is dominated by Paul's instructions to those who are married or who have been married.
The Greek word for "widower" was not in use during the Koine period.
The word for "unmarried" appears to be the masculine word for someone who has lost a spouse.
As a good Pharisee, it is highly unlikely that Paul would have been single his entire life.