Technically, no problem at all. As long as the client knows what he has when he does a weld repair in 20 years time.
But, if you are working to a code, it's a problem. You have two options: (i) cut out and replace; or (ii) qualify a procedure to cover the way your weld was made.
p.s., send your welder back to school. SMAW electrodes are all labeled with the AWS classification. If it's not legible then it may not be coming from a reputable maker.
"Everyone is entitled to their own opinions, but they are not entitled to their own facts."