The way it “should” have went down:
- Yelich (runner on 2nd) gets caught between bases. It’s only a matter of time now, so try and stall as long as you can. This buys time for:
- Cain (runner on 1st) immediately takes off for second. He can stay on 1st and watch his friend get tagged out, or get to 2nd and watch his friend get tagged out.
- Now both runners are on second. Fielders tag whoever they want. One out, one runner on 2nd.
I’m sure the Cub saw another Brewer at 2nd, and thought he would get a tag out on one of them standing on the bag. Notice he still has the ball in his glove. Rule in a pickle is always get it out of your glove - it doesn’t do any good in there.
The Cubs screwed up having the 1st baseman leave the bag, which would have kept Cain honest. Cain noticed, caused enough confusion to let Yelich get back safely, and ran back to 1st with nobody covering.