Depends how badly they fall out of it.
If they literally fall down on the entrance or otherwise fail to spin or stop spinning before 3 revolutions, even if they start it up again and fill the rest of the planned spinning time with good spinning, they'll get no credit for the element. And a -1.00fall deduction for an actual fall..
If they fall or fall out after 3 revolutions then it will be called as a spin, quite likely lower level than intended, and the judges will give negative GOE. And a -1.00 fall deduction for an actual fall.
Worst-case scenario:
Fall to the ice on the entry to the spin. Called as the spin with no level and no point value, and -1.00 fall deduction. Net score: -1.00
Other scenarios:
A good flying camel spin or a change-foot camel spin with several features and plenty of revolutions and then fall down before exiting the spin. Could be level 4 with average -2 GOE (+1 for the majority of the spin and then -3 for the fall), and -1.00 fall deduction. 3.0 base mark, -1.0 GOE (the minuses are worth less than 1.0 each for elements with lower base marks), so 2.0 for the element and -1.00 deduction for the fall. Net score: +1.00
Combo spin started with a shaky, badly positioned and badly centered camel barely held for 3-4 revolutions, loss of balance and "fall" out to the other foot, but manages to save the foot down into a change of foot to the second half of the planned spin, adequately executed with two features. Level 2 combo spin base mark 2.5, probably -3 GOE (touchdown of the free foot and not enough revolutions on the first half of the spin, worth -1.5). No fall deduction. Net score: +1.00.
Other variations of these scenarios are possible. With lower level spins and actual falls, the net score is more likely to be negative.