
The loss meant that the Blues fell to back-to-back defeats in their opening two league games for the first time since the 2014/15 season.
And Bullock had mixed feelings over the nature of the Northern Premier League Premier Division defeat.
"I thought in the first half Liversedge really put us under pressure with long throws and set pieces into the box," Bullock said.
"The team we had out, we had two recognised headers of the ball on the pitch.
"The two goals we've conceded, we haven't been strong enough.
"That's no disrespect to the lads but we just got overpowered.
"After 25 minutes we stood up to it a bit more, and in the second half some of the play was electric, but it's the same story again.
"We haven't stuck the ball away.
"They've gone up the other end, won a free-kick and scored. It's a massive bitter pill and feels like a smash and grab."
Whitby opened the scoring inside 15 minutes, when good build-up play from Whitby saw Marcus Giles fire low into the bottom corner, inside the near post.
However, just eight minutes later, the newly-promoted visitors levelled matters when Jack Stockdill bundled the ball over the line in the area.
And moments later they led. A free-kick from deep was centred before James Hurtley tapped home in a similar fashion.
Whitby levelled matters five minutes before the break.
Harry Green latched onto a clearance from the Blues defence, before finishing well inside the box.
The Seasiders dominated the opening stages of the second half, moving the ball quickly around the Liversedge side.
However, despite the pressure from Whitby, they couldn't find the net.
Lewis Hawkins went closest, cracking the bar, while Giles fired over the bar inside the box from a good position.
Ultimately the Seasiders were punished 13 minutes from time, when Paul Walker drove a low free-kick around the wall from twenty yards past Shane Bland.