It's a design issue in the sense the smaller cams cannot take the torquing force when placed in such way the cam is not free to rotate into the direction of the fall.

You can say it's not designed to handle such situation or what not, but these placements do come up now and then and some cams deal with it much better than others.

The issues I see:

1) head width: aliens have narrower head, and thus the axle does not take as much torquing force as an equivalent sized C4. Wider head also exacerbates the problem when placed in a shallow crack as it requires more depth to rotate/orient.

2) single vs dual axle, the latter has thinner axles, does not have the cam lobes completely wrapped around the axle, and is possibly more susceptible to axle bending/lobe warping

3) stem flexibility: stems on WC Zeros are flexible all the way to the axle (unique to all single stem cams in the smaller sizes), therefore having a much shorter lever to generate torquing force, the C4s, on the other hand, from size 1 (red) down, has stem that's rigid about 1 inch from the axle.

So call it design issue or weakness, fact is, there are other types of cams that could've handle the fall in the same placement better (at least in the sense of not rendering the cam inoperable).