Unless I am mistaken the aircraft did not get into Class B airspace..
Burbank is class C, Van Nuys is D, and from there the track would have taken him into Class G airspace.
SVFR in both the C and D is legal with an ATC Clearance which he had for each Control Zone.
Once in Class G airspace, 91.155(a) visibility minima is one half statute mile and clear of cloud.