Please answer the following question: Given the following context:  In the summer of 1940, world-weary Harry Morgan operates a small fishing-boat, the Queen Conch, in Fort-de-France, on the French colony of Martinique.  It is not long since the fall of France and the island is controlled by pro-German Vichy France. Harry makes a modest living chartering his fishing boat to tourists, along with his unofficial mate Eddie. Eddie is Harry's close friend and one time trusted co-worker, but he has of late become an alcoholic. The island is a tinder-box of dissent, harboring many people sympathetic to Free France. At his hotel home, hotel owner Gérard (known as "Frenchy" to English speakers) urges Harry to help the French Resistance by smuggling some people off the island. Harry steadfastly refuses, choosing to keep aloof from the current political situation. Also at the hotel, he meets Marie Browning, a young American wanderer who has recently arrived in Martinique. An accomplished singer, she sings "How Little We Know" with pianist Cricket in the hotel bar. Harry's current charter client, Johnson, owes Harry $825. Johnson insists he hasn't enough ready money, but promises to get the funds when the banks open the next day. In the hotel bar, Harry notices Slim pick Johnson's pocket and he later forces her to hand over the wallet. On inspection the wallet is found to contain $1,400 in traveler's cheques and a plane ticket for early the next morning (before the banks are open). On returning the wallet to Johnson, Harry demands that Johnson sign the traveler's cheques to pay him immediately. But just then, there is a shootout in front of the hotel between police and the Resistance, and Johnson is killed by a stray bullet. The police take Harry and several others for questioning, and seize Harry's passport and money.  answer the following question:  Who stole Johnon's wallet?
Answer:
Slim