Pip claim

Husband has just rang to do a new pip claim. During the conversation with the lady he couldn’t answer some of the questions like his mobile number got the house number wrong. When she’d finished giving all her speal I asked if he could have the form emailed out to him, she said no because it’s a third party claim because I’d answered some of the questions. I said well I had mine emailed to me as I can’t physically write the form out due to my arthritis. She just replied again I can’t as it’s a third party claim. Should we call the other number and ask them if they can email it ? Or is this correct. I can’t find anything about a third person claim for pip when I did a search. Am I missing something ?
Thanks