That was what I thought. He could easily get closer to "that" tone if he wanted to.
It's surprising when you realise a lot of our most desired and emulated bass tones were the result of necessity rather than choice. Roger Glover has often said his famous Machine Head Rickenbacker tone was not to his taste at all, being overly distorted, and was an attempt to cut through Blackmore and Lord's din. He's very happy with his current Vigier tone, but that sounds bone dry and sterile to my ears.
See also, Geezer Butler. His early tone with Sabbath - Fender Precision with flats through faulty amp/speaker was literally the best he could do.