I will give that the bearing may have been slightly over packed. However, since the grease is still clear it didn't overheat and burn the grease.

Please give us a detailed description of the sealing mechanism on a double sealed bearing.


https://www.ntnglobal.com/en/products/review/pdf/NTN_TR81_en_104p.pdf

This paper states methods of reducing grease leakage through cage design. It is very reasonable to deduce that some grease leakage is normal.


http://www.nachiamerica.com/download/75/Deep-Groove-Ball-Bearings

The chart on page 3 states that with a contact type rubber seal, grease may leak from the bearing at high speeds / high temps.