We are aware of the issues which have arisen regarding Friday's A level maths paper. We are in communication with Edexcel about this and will provide an update as soon as we have more information. Although this is an unfortunate incident, all examination boards have tried and tested protocols to deal which these events.
Please see the official statement from Edexcel below:

qualifications.pearson.com/en/subjects/mathematics.updates.html?article=/content/demo/en/news-policy/qualifications/edexcel-gcses/mathematics/statement-on-a-level-maths&pageTypes=