Why didn't you get the V5?
he hasn't transferred it?
It is his responsibility.
Yes, it won't be a problem. At least it will be his problem not yours.
You have to notify the DVLA of this situation and request that they transfer to you. They will write the previous owner for comments but obviously he will not want to be liable for your speeding offences or parking fines potentially. He has probably just forgotten to do it.It won't be a problem.
Can I clarify anything for you?