Further more, the force was negligible.
Negligible is subjective
This. Literally the ONLY people who truly know how hard the contact was, are Wissa and Gilmour. Every single other person's perception of the force - be they referee, VAR official, commentator, pundit, Amex crowd or TV viewer - is based ENTIRELY on Billy Gilmour's reaction to the contact.
Had Gilmour reacted as many less honest PL players would surely have, Wissa would undoubtedly have been dismissed, and that decision would have not raised an eyebrow.