Mistakes happen, deal with it. Merc obviously though they had enough time to get him in and out first. If I remember the call was made under VSC conditions, which would have been fine as the field was holding station and distance. When the sc came out the field were able to close up and reduce the gaps, meaning there was less time to change shoes. This is where Merc made the mistake, as soon as the sc came out they should have waved him on.