Customer helplines that use recorded menus that promise to put me through to the right person but never do - and being ill. Oh, and did I mention customer helplines :)
Long answer______________ Yes it was. All carbs turn to glucose and bread is one of the fastest carbs to be broke down so it hits your blood stream in one hit (as it were) Lower GI foods like Burgen are broken down more slowly so enter your blood stream more slowly and therefore cause less of a peak in bg levels.
Wholemeal bread/rolls are just the same as white bread/rolls, wholegrain breads and rolls are generally better but not all wholegrain breads are low GI so you need to test. But all white and wholemeal breads and rolls will have this effect to most T2 diabetics.
Wholemeal still contains lots of carbs but if it is proper wholemeal, it should release it more slowly, depending on how it's milled. But, a bit of wholemeal means your bread was probably nearly all white four.
I have the same problems with nan breads and chappatis. Most are rubbish, only a few are OK depsite all being labelled wholemeal or wholegrain.
I agree with others that yes the roll could push your bg by that much, often if a filling contains fat it can slow down the absorption... but as your a diet controlled type 2 I don't think it will make much difference.