Lowe's Home Improvement interview questions

Applied online then went to my Lowe's store and spoke with the HR Manager personally. I received a call from her the following week to be interviewed. I first interviewed with HR Manager, then Asst Store Manager, then I was to interview with the Store Manager but he was unavailable so I was asked to come in the following day. After an interview with the Store Manger, the HR Manager administered an oral drug test. A few days to a week later, the HR Manager called me at home and made me an offer of employment.

Very quick response on initial interview, interviewed with HR & asst. manager, called back week later with store mgr. Next store manager interview will call in three days, no call, called HR, mgr scheduled 2 meeting today, asst. manager talked , store manager had me evaluate customer service in store while he was doing something, asst manager went over with me about cust. service in store, Mgr in HR office with door open he could hear our discussion. Then after being there a total of one hour mgr comes in and say he will get back with me on Monday????? No offer, No drug test what is up?