I’ve seen it happen both ways.
If a consecrated Host falls all the way to the floor, it instantly reminds me of Our Blessed Lord falling when He carried the Cross.
In my long-term and palliative care apostolate, some patients have very dry tongues which increase the risk of a Host falling - even when placed directly on the tongue.
Arguably the most difficult situations I’ve dealt with personally, involve patients suffering from dysphagia (an illness [often post-stroke] which renders them unable to swallow…or only with extreme difficulty). They can only be given a fragment of the Host - about the size of the lead tip of a sharpened pencil.
It’s a very delicate situation. This fragment is so light that even the patient’s breath can propel it into the air. On occasion it can also take all the dexterity one can muster to hold the tiny Fragment between the thumb and forefinger while administering Holy Communion.
Several instances where the patient’s breath or cough has propelled the Fragment, or it has slipped through the fingers while attempting to administer have occurred and it compicates things.
There have been 4 occasions in the 13 years + apostolate where this happened and, with white patients’ clothes, white bedclothes and a white floor, it has been physically impossible to find the fragment.
Especially at those times, I’ve invoked the ministry of the Holy Angels, asking God that they come and gather up this piece of His sacred Body which I am unable to find.