As far as I know, having a regular lunch spot isn't suspicious.
The issue here is 2 dimensional. Whilst most of you are shedding tears for Morells grievous violation of anonymity, I look at the police officers point of view...
They are not infallable. They do not carry perfect hindsight/foresight.
How the dickens do they know, that Morells is a innocent man, just eating his lunch ?
It is part of their job to be suspicious and cautious. To be completely unassuming and oblivious would be putting the community at risk.