Errors Can Occur in DNA Codons read incorrectly

Lets consider DNA as a three letter codon.............TGC 1/7 read from left to right creates Cysteine but TGC read from right to left creates CGT 1/4 Arganine so if you had a pile of three letter codons in a heap and had to make a string of DNA from it errors could occur......... they dont literally have the letters written on them so they could be three squares of colour. Its more difficult to know its an error then. There are situations when arginine to cysteine mutations do occur......could this simple error be at fault. 

If we take ATA there would be no change as ATA reads the same in both directions. This simple fact reduces the number of three part patterns required for DNA from 64 to 40 ........its hard to add on at these points in the game Soloman’s Temple because it causes a repeating pattern. 

TAC 1/3 Tyrosine and CAT 1/8 Histidine there are not many codons that make these amino acids.  Mutation of Histidine or Tyrosine do occur. The fact is that any protein that is not in its correct position will cause some form of mutation or error code. 

GAT 7/9 Aspartic Acid and TAG 4/9 STOP Amber............are there issues associated with this as an error or does Aspartic Acid 7/9 version STOP any errors occurring.  Another Aspartic Acid GAC 7/3 would partner in error with CAG 4/8 Glutamine so there are two Aspartic Acids GAT and GAC both would partner in error with different codons. 

TGC from left to right and CGT from right to left.