I Took My 4 1/2 Year Old Grandson To Get

i took my 4 1/2 year old grandson to get his final vaccine. the nurse said he needed mmr and although i thought i had taken him for that several months back i assumed they knew what they were doing. they gave it to him and when i told his mother she remembered he had it and called to check with the dr's office and indeed he had it in July. is there any danger in him having it again today about 6 months later? this child had terrible reactions following the 1 year old vaccines, we lost him so to speak for about 3-4 weeks. we were lucky that he returned to his former normal activities and from then on we really spread out the vaccines. we are very worried that the dr's office made this mistake. should we be worried and if so what can we do if anything. he only just had it today at 4pm