I think the in the olden days (pre WWII) a Kendoka was allowed to continue the match without the shinai, emty handed.
Yes, pre-war kendo allowed for all sorts of things that are no longer considered "proper" kendo, though foot sweeps are still permissible in some police tournaments. This is in part because the shinai kyogi faction won out in the end after the war after it merged with the ZNKR in 1954, and written laments of teachers in the 50's and 60's who stated that kendo lost its way.
People tend to focus on the grappling aspects of pre-war kendo such as choking out aite with a do, or ripping off the men, but seem unaware that were whole sets of waza which were more or less discarded.
Getting back to the original topic, you will find a number of pre-war teachers who state that kendo and judo were two sides to the same coin.