Do airline pilots really do this???
In this case, yes. To summarize from the report, they did a normal INS "fast align" (30 seconds) at the gate, but the FO entered the erroneous E and then did not notice the FMC error message warning that the position entered was not close to the gate position in the FMC data base.
At the holding point they noticed the error, put the INS in Align mode, entered the correct Longitude and started the "fast align" again. At this point they were cleared for take off and started to taxi before the alignment was finished, so they departed with no attitude or nav data on the displays. They also left the INS in Align rather than Nav mode.