Compiler outputs suboptimal miniscript for `or(pk(k1),pk(k2))`

The second policy example at https://bitcoin.sipa.be/miniscript/ 

"One of two keys (equally likely)" - `or(pk(key_1),pk(key_2)))` - compiles to `or_b(pk(key_1),s:pk(key_2))`.

Should it not compile to `multi(1,key_1,key_2)` instead, which has the same witness size but a smaller script size (71 WU vs 72 WU)?