My answer to the question. Edit
For some reason it's not letting me post the answer to this question so I'll post it here.
- Nicholas Courtney had passed away in February 2011. The Brigadier's death in The Wedding of River Song was intended as a tribute to Nick. The death of the Doctor's oldest friend is what causes him to accept his. Furthermore, the eyedrives were also a tribute to Nick, having cited Inferno as his favourite Doctor Who story. In Inferno, the Brigade Leader wore an eyepatch. Commander Linx 02:51, May 27, 2012 (UTC)