Engineering interview candidate refuses to use whiteboard [duplicate]

Question

This question already has an answer here:

• Is “White-Board-Coding” inappropriate during interviews? [closed] 13 answers

Today I experienced a first in a technical interview. The candidate refused to use the whiteboard to solve an algorithm question, as I requested. There was no sort of disability at play or anything (outside of nervousness). He simply said that he is uncomfortable using a whiteboard for difficult questions.

Oddly enough, we were able to work through it with me standing over his shoulder looking at his notepad. He even communicated his thoughts effectively enough for me to help him over the inevitable bumps. After this I asked him how he felt about collaborative work (as collaboration here is heavy) and he said he loves it. I asked him if he likes to get together with other developers to hash over problems on the whiteboard to which he said yes.

Is this some sort of red flag or am I just reading too much into this? In our environment, collaboration is a must.

ADDITIONAL DETAIL:

The candidate was being evaluated for a lead development position, in which case he spends much of his time communicating with his developers and less time coding than an individual contributor.