Accused seems like an odd word to use here. In UK and US jurisdictions the fact that you used a proxy to commit a crime does not make any difference to the scale of the crime does it?
Then, sometimes, journalists use terms they shouldn't. Maybe that wasn't a "real" proxy (according to the definition of a proxy), but a simple "bounce" (a hacked box/server somewhere), in which case it is illegal (for example he hacks a-company.com, installs a socks server and tunnels his traffic to this socks server.)
I imagine it could have some implications when discussing the level of pre-mediatation as well. For example, if you were doing the tech equivalent of a 'crime of passion', then having set up multiple layers of proxy servers will undo your 'spur of the moment' defense.