He was in a pretty low performance glider, so at the speeds he appeared to be flying (to get though the sink) he'd have been dropping like a brick.
Overall he did get a couple of early decisions wrong but at least didn't just press on for the gap with fingers crossed. Approach speed was too high - brakes and sideslipping might have mitigated the touchdown speed but overall he got away with it personally and the glider was repairable so the landing site choice was ultimately a good decision!
Hindsight's a wonderful thing. Glad it wasn't me.