You are technically correct - but in actuality the electorate is intending to vote for the head of state - so I think in practice this technicality doesn't invalidate the general statement that folks are voting for a head of state.

The distinction you're highlighting is a very important piece when it comes to discussing election reform, but I think it's better to classify it as an inaccuracy in the manner in which the electorate votes for the head of state - rather than as the electorate not voting for a head of state.