Apple already had the eMate 300. https://en.wikipedia.org/wiki/EMate_300

And Acorn (the company that invented ARM chips - Acorn Risc Machine) had the Acorn A4 http://www.computinghistory.org.uk/det/22807/Acorn-A4-Laptop... Edit: Microsoft was also already there with their Windows CE devices.

And Psion and Vtech (http://www.computinghistory.org.uk/det/30249/Vtech-I-T-Lapto...) also used ARM Chips in laptop form factor devices

So it's not really about someone beating someone else to market, just the evolution of the market itself.