I (my friend really) need some help!

A friend of mine was due to leave Lisbon with a LIS (BA)-LHR (CX)-HKG itin, purchased on Expedia.

During check in, a BA Ground Crew has attached a barcode to one of his belongings - an iMac in original box inside that was to be scanned by security. My friend arrived at the security area but the barcode did not scan through. It took some time to resolve and ultimately my friend was unable to catch the flight.

BA proposed to reissue the ticket to let him fly tomorrow, 23/06, which means a minimum delay of 24 hours. My friend did not accept and proposed to leave on 25/06 due to personal reasons. BA has accepted.

Questions:
1) Is EC261 applicable? (I assume not)
2) Does BA have any duty of care? If so, how long?