[greymule]

The Fed 2002 Case Book worded the ruling slightly differently.

8.2.3 Situation: B1 hits a slow roller to F5 and arrives safely but misses first base. F3 catches the ball and casually steps on first base, though he believes the runner has beaten the throw. Ruling: B1 is out. Because a force play is being made on the runner and is the result of continuing action, F3 is not required to appeal the missed base and needs only to complete the force out.

The above play was marked with an asterisk to indicate a new or revised ruling. See below.

Fed 2001 Case Book:

8.2.3. Situation: B1 hits a slow roller to F5 and arrives safely but misses first base. F3 catches ball and casually steps on first base, though he knows runner has beaten throw. Ruling: B1 is out. Play is being made on runner even though F3 is unaware that B1 missed the base.

It appears that in 2002 Fed included "continuing action" to prevent some of the ridiculous scenarios people were coming up with for the accidental force play (e.g., F4 kicks dirt off 2B as he walks the ball in, forced runner misses 2B and slides safely into 3B where F5 casually tags him and produces accidental force out, pickoff attempt before next pitch happens to be at missed force base, etc.).