You are right in the lottery sense : if your particular phone or app crashes, it is very unlikely that it is due to cosmic rays. However, it might be likely that it happens fairly often around the world. This is similar to the lottery : it is unlikely that you will win, but it is likely that someone will win.
It's all a matter of cross-section of the devices actually. If we want to compare, the IPhone 4 (an old baseline, smaller than today's generation but close to most of the low-cost devices) measures 0.007 m^2, while the top 10 largest data centers (from this random link) combined measure about 1.7 x 10^6 m^2. I am going to assume only 1% of the surface is occupied by sensitive chips (?). You would need about 2.4 millions IPhone 4 to cover the same area. Thus, it is very possible that mobile hardware is victim of more high energy burps than immobile hardware.