Agreed, I don't rely on airlock observations at all. Often, I will just use foil instead of an airlock.
Dry yeasts are so healthy that you shouldn't get any off flavors. Remember though, pitching dry straight into wort will kill ~50% of the packet. Pitching straight into beer (with alcohol) will reduce the number of viable cells even further. You likely didn't over-pitch nearly what you think you have. If, and I stress if, there were any concerns, it would be with the number of dead yeast cells.
Myself, I would dump the yeast as soon as I could, and then enjoy the beer!