Safeguarding risk as follows..
unknown bloke in a heightened state on the very very edge of a platform waiting for a train. Potentially impulsive and reactive bloke. Not known if drugs or alcohol involved. Not known if he will become physical if someone approaches.
lone woman
nothing is known about historic mental health, historic police involvement, historic dynamics with women. Does he carry weapons?
quiet train station, few people around.
inviting him for a drink would likely give the impression of a hook up
it would be safer for blokes or a couple to approach him. Alternatively a lone woman could notify a guard.