Is the person wasting time excessively? as a way of life? Is the person wasting time as a breather or is the person taking a break or a vacation? Is it done in a controlled and a beneficial manner in order to recharge their batteries or is the person just being lazy?

Sometimes it's difficult to evaluate because the person usually justifies his actions as being the right way to do it so sometimes there are things which are done which should not be done but the person presents it as they are doing the right thing. Indeed they do have to justify their actions at least to themselves or to rationalize their actions and this could be problematic.

Wasting time is not in itself inherently bad. It is not a negative trait. It is important to be able to shift from work and the concept of "all work and no play" is the negative effects of all work and no play are known to all.

Indeed, too much work can have as much of a negative impact as too much laziness and it is important to find the right balance between the two of them.

Are they making the most of their time? Perhaps they can get some work done during irregular hours.