I had never thought of it before, but:
For there genuinely to be nothing else happening the lift and pitch balances must be satisfied simultaneously.
If the aircraft started in trimmed 1g flight then the incremental wing and elevon lifts must be equal and opposite to remain in 1g flight
Applying that condition to the pitch balance the algebra says the aircraft can only stay in pitch trim if the wing incremental lift and elevon lift act at the same point.
For normal flight/free air one would throw this out as a load of cobblers, but as a delta wing flies into the ground cushion the wing lift moves a long way aft - possibly to around 70ish% chord. I do not know what the elevon lift does in ground effect, but would not expect it to go any further forward than that.
So technically it could be possible, but would depend very much on the airplane and the height at which the manoeuvre was attempted.
I seem to remember somewhere in the Concorde question thread a pilot posted that allowing the stick to move forward during the flare was a prelude to disaster.
I tries to find the posting but gave up at #600!