aspect='equal' argument is completely misused by axes3D.
To verify:

import matplotlib.pyplot as plt
from mpl_toolkits import mplot3d
fig = plt.figure()
ax = fig.add_subplot((111), aspect='equal', projection='3d')
ax.scatter((1, 2), (1, 1.2), (1, 2)) 

• The figure is rendered with all axes scaled to the data scale, thus ignoring the aspect setting.
• If one tries to rotate the figure, using GUI, it is rescaled to fix into a very uneven rectangle, presumably calculated from x-scale vs y-scale, and hence with aspect ratio 1:5.