I don't participate or play VNEA, but here are the rules that I found online.
http://www.vnea.com/8-ball-rules.aspx
For the OP's situation, VNEA rules C, E and G appears to address this.
C. OPEN TABLE
..The choice of group is determined only when a player legally pockets a called object ball after the break shot.
E. PLAY
1. If a shooter inadvertently pockets his opponents ball, it remains down, however, if the shooter does not legally pocket one of his own group, he loses his turn.
2. Each player continues to shoot so long as he legally pockets any of his object balls (Exception: calling a safety). Should a player fail to pocket his designated group ball, he shall lose his turn.
G. LEGAL SHOTS
On all shots (exception: page 11C and on the break), the shooter must hit one of his group of balls first and (1) pocket any group ball, or (2) cause the cue ball or any other ball to contact a rail.
* (There are two groups of balls: stripes and solids)
...
“SAFETY” SHOT: For tactical reasons a player may choose to pocket an obvious object ball and also discontinue his turn at the table by declaring “safety” in advance. A safety shot is defined as a legal shot. If the shooting player intends to play safe by pocketing an obvious object ball, then prior to the shot, he must declare a “safety” to his opponent. If this is NOT done, and one of the shooter’s object balls is pocketed, the shooter will be required to shoot again. Any ball pocketed on a safety shot remains pocketed.
Okay, how about "I'm playing safe and shooting the 12 in the corner".
I'm trying to prove a point about a bad rule. I have yet to see the documentation, but according to the VNEA rules, you can establish your balls AND play safe in the same shot. And apparently, if it's an obvious shot, you don't have to call the ball or pocket at all.