was on same flight... bit chaotic but would have been better if someone had explained what was going on!
got text 4 hours later..

Bit o/t but leaving AMS on KLM separate check of documents at a gate before the main departure gate ; travelling to Manchester but also passengers to Heathrow had to do same but bizarrely not those travelling to other UK destinations such as Birmingham or Bristol!

The KLM agent nor the chap doing the document checks didn't know why the differentiation either!