The new Cheltenham boss saw Omari Sterling-James fire his side ahead in the first half but the winger probably should then have made it 2-0 with a one-on-one opportunity.
Jones, however, had other ideas and made a good stop before Pompey went straight up the other end and equalised through Nigel Atangana.
Buckle said: ‘We could have been 2-0 up.
‘I suppose it was too good to be true.
‘I gave Omari a new deal this week, he scored a cracking first goal and looked a threat all day. When he went in on goal, I fancied him to score and it was a crucial time in the game.
‘If that went in, it would have been a different story.
‘But Paul Jones is a good keeper, he stood up well and they went up the other end and scored.
‘It’s all about fine margins.’
Although he was delighted with his team’s efforts in the first half, Buckle felt his men were unfortunate to concede in the way they did.
He said: ‘I thought we scored a brilliant goal.
‘We were 1-0 up at half-time and we knew they would come at us in the second half.
‘You could tell Andy wasn’t happy.
‘But they threw a lot into our box and we coped with that.
‘We just lost our shape for one moment, which allowed the centre-back to come through and then the shot took a wicked deflection and went in off the underside of the crossbar.
‘Then there was a huge test of character for us but I think we held out fairly comfortably in the end.’
He added: ‘Pompey are a massive club and I’m sure Andy won’t mind me saying they have a lot more money than us.
‘But on another day, we could have won that game.
‘I suppose we have to be happy with a point.’
– STEVE WILSON