Many cities have either their own code on allowable load for nails and bolts or have adopted a uniform building code.
In Los Angeles for example the building department has published these codes on their site, or give them to you as a hand out for free.
American Wood Council has many pages of guidelines and information on their site.their calculator The allowable load for wood connections depends on many factors:
wood structural rating, its humidity content, species, storage history as well as mechanical strength and type of fastener (screw, bolt, lag bolt, prefabricated fasteners and kits) and the mode of their failure( shear, bending moment, pull out, etc..) and alos the function of the connection, there are load factors for seismic loads or shear loads, etc.
For nails there are concerns as to the ductility of nail, its size and length, the distance between nails, the grain of wood and its angle and many more factors. All of these cases have been extensively tested and tabulated and are available from your City or the hardware store or the manufacturers site.
A deputy structural engineer inspecting the construction site is responsible for checking the nailing and proper application of their use and will ask the builder to correct or remove not complying nails, fasteners or members and re-installing them correctly.
You have to discuss your case with an engineer in your building department. In most cases it is free consultation.