We are told that the Sar Hamashqim forgets Joseph in the last Passuq of Parshat Vayeishev, (40:23) "v'lo zochar Sar Hamashkim et Yoseif." Rashi comments, "Huzqaq l'ihyot assur sh'tei shanim"
Most understand this as just a "2-minute penalty" for lacking Bitachon in Hashem. Joseph wound up in the penalty box for two years! Is this a punishment? Does this teach us to rely only upon Hashem and not use our own resources?
Remember that old joke? The one about the fellow in the flood to whom Hashem sent a car, a a rowboat and finally a helicopter and he refused each ride and drowned while waiting for Hashem to rescue him?
It seems harsh to blame Joseph for being resourceful in own rescue! Why punish him for lacking Bitachon?
Let's take a look at an Abarbanel in the Haggadah. Abarbanel writes that, "had HKBH NOT rescued us then "M'shubadim Hayyini l'Faroh." In other words, had Pharaoh freed us instead of Hashem, we would have been indebted - not enslaved - to Pharaoh. Think back, American slaves felt indebted to Lincoln, not to G-d.
Similarly, what if the Sar Hamashqim had freed Joseph? Joseph might have felt indebted to him. Instead, huzqaq, so the sar hamashqim would forget Joseph. Hashem wanted Yosef indebted to Himself alone.
Joseph might have learned the wrong lesson had he successfully used the Sar Hamashqim to rescue him. We also might learn the wrong lesson if we see Joseph "blamed" and not "taught".