I think it's possible, but it becomes less and less likely with the depth of the latches. Supposing your keyboard key input was latched by a flop and you press

I think it's possible, but it becomes less and less likely with the depth of the latches. Supposing your keyboard key input was latched by a flop and you pressed the key at the exact right moment you could violate the timings of the flop and have it end up in a metastable state. That's why you usually put a bunch of delay flops when sampling such a signal in the hope that you'll manage to have a stable signal down the line, however that doesn't remove the problem altogether, it just makes the probability of the problem happening very low.