In the absence of Initiation Factors the 30S mRNA initiation complex is quite stable . The error rate approximate 1 mutation in 10,000 amino acids incorporated. Suppressor strains exist. In the supF background this particular mutation need not be lethal as, every so often, an aminoacylated suppressor tRNA can insert in to the ribosome during translation of this mRNA and translation at this particular seesin of translation will be able to continue to the normal end of the structural gene. Hopefully the protein can accommodate a tyrosine at the position of the mutation.
Additional evidence exists.
Experiment involving cystine converted into alanine after aminoacylation takes place. The polypeptide is subsequently released and the ribosome falls apart. The requirements for reinitiation of a downstream sequence are not as stringent as are those for initiation. Cistrons, operons and their coordinate regulatory requirements. The requirements for re-initiation of a downstream sequence are not as stringent as are those for initiation.