Powell criticised referee Gary Sutton's decision to banish him from his techincal area after the pair exchanged words at the end of the first half.
Sutton's failure to award a penalty after Yann Kermorgant appeared to be fouled in the area was one of the incidents which frustrated Powell and he was forced to watch the second half from the directors' box, although he was told by the referee that it was not an official sending-off.
Wednesday left with the three points after Rhys McCabe gave the hosts a 20th-minute lead with a superb volley and Jeremy Helan added a second in stoppage time with a good, angled finish.
"It looked a penalty but the referee has got to make a quick decision and maybe it's that little of luck we've been missing," Jones said.
"We had a shaky start and they could have scored a goal in the first two or three minutes but after that we sorted ourselves out and I thought we were worthy winners in the end.
"Rhys McCabe scored a great goal and he's certainly capable of doing that. We've seen him do it a lot in training and I'm just pleased for him because he's a good young player who's learning his trade.
"There's a long way to go and we're fighting for our lives. What we maybe lack sometimes in terms of a little bit of quality, we make up for in endeavour and commitment and that's all you can ask for.
"As this shows, if they work hard and keep that going, they'll win more than they lose."