You would have to have at least a million sample hands before you could even suggest anything improper here. Even if the odds were 100:1 of this happening it WILL happen 1 in 100 times and to think because it happened to you that it is shady software is impractical.
The theory is that if the dealer had 19 that it would be just as rigged in your favor, which is non sense. You just had a losing hand. Thats all.