This all depends on individuals, there are certain people that can easily be distracted by an itch or move or noise especially when their mental faculty is weak and not strong enough to resist distractions or can not diversify their in a particular time and actualizes their aim especially when it is something technical.

So this gambler in question could fall in any of that. Maybe we can assume this to be possible regarding that the processes of analysing games with an aim of winning would require an extreme attention.