בעי ר' אשי הגביה ארנקי (Bava Metzia 44a)

The Gemara says that Shmuel could even be according to those who hold that שליחות יד צריכה חסרון and this case is different because he wants the רביעית of wine in the barrel so that it stays better. R' Ashi then asks what about ארנקי? The simple understanding of the Gemara is that R' Ashi's whole question is only if שליחות יד צריכה חסרון but if שליחות יד אינה צריכה חסרון then the case of ארנקי is a classic case of שליחות יד (since at the time he is מגביה he has כוונה to be מחסר by taking out a דינר) and he is for sure חייב. In fact, this is the way the Rif, Rosh and Tur pasken. However, the Rambam (הל' גזילה ג:י"ב) even though he paskens that שליחות יד אינה צריכה חסרון brings down the case of R' Ashi as a ספק how to pasken. We see from the Rambam that he held that R' Ashi's question was even if you hold שליחות יד אינה צריכה חסרון. The Acharonim work hard to understand how the Rambam could say this.