My instinct is that if not Islamic it will be labelled as mental illness or cannabis psychosis.Lots of Indians (and Chinese) were 'encouraged' to work there over 100 years ago when slavery was abolished - so plenty of descendants. That could be an explanation
Plod may have just rounded up the only non-white passenger on the train as a potential suspect. Probably not heard the last of this
The scariest thing would be if this was just anger.