A quick correction to my post:

Here's where the truly novel part comes in. Ruben solves this by extending the standard *TLC contract:
1. Bob redeem with secret
2. Alice refund after T1
3. Bob redeem without secret after T2

This is actually:

1. Bob redeem with redeem secret
2. Alice refund after T1 with refund secret
3. Bob redeem without secret after T2

The fact that Alice reveals a secret when she refunds is crucial.

LL