Among the elite of each respective style, yes.
Sambo
1.) Fedor has only missed one sub and that was against a 7'2'' 360 pound Korean.
2.) Fujii hasn't missed any that I recall. She's also number 1 PFP and undefeated like Fedor. She won by submission 12 out of 15 fights.
3.) Amir didn't miss any in his short, but potentially promising career.
BJJ
1.) Jacare missed numerous sub attempts. In his fight with Mayhem alone he had numerous chances to sub him. There is even a picture of Mayhem laughing at his leg lock attempt.
2.) Arona has missed numerous sub attempts as well. The fight against Rampage comes to mind or even his LnP against Fedor. In fact, Fedor reversed Arona from mount many a time. Arona's also lucky RINGS didn't allow GnP.
3.) Pe de Pano couldn't even sub Arlovski on the ground. Arlovski had no problem defending on the ground and as soon as Herb-A-Dean stepped away he GnPed PDP to hell.
Atr you fucking kidding me? So Amir and Fedor only went for 1 sub once in all their fights they wpn bysub? Get real. Your an idiot.