That's right... When Ringo temporaly got out of the band because he was bored and feeling useless for the group, Paul took seat on drums and played those songs on White Album. I could find some others: "Wild Honey Pie"; "Martha my Dear" and "Why don't we do it in the road?(with Ringo)". And on the single "TBOJY", requestesd by John, beyond drums, he played piano and did the backing vocal just for solidarity for him. George and Ringo wasn't present. I don't know if there's another track he played drums.
"The Who"'s Keith Moon once asked to Paul who was played drums on BOTR album and wonder how was a pretty good drummer, Paul replied: "Well...by chance, it was just me!".