What if there is no rebirth but karma is not eradicated by meditation and the path? What if there is no rebirth but karma is not eradicated by the path?

I think that would mean that the agent experiences the results of their actions even without rebirth. Am I right? At least if the buddha self is not just impermanent.
There is no 'rebirth' (aka 'reincarnation') but kamma (the idea of 'agent' doing &amp; reaping) is eradicated by the path. This means if the path is not realised, 'the agent' experiences the results of their actions even if there is no rebirth (reincarnation). 

However, 'an agent' experiencing the results of their actions is what 'rebirth' really means. 'Rebirth' in reality is the re-arising of the idea of 'the agent' or 'self'. 

'Rebirth' does not mean 'reincarnation' into another life. 'Rebirth' means the idea, obsession and neurosis of 'self' keeps getting born; as follows:


  There is the case where an uninstructed, run-of-the-mill person — who
  has no regard for noble ones, is not well-versed or disciplined in
  their Dhamma; who has no regard for men of integrity, is not
  well-versed or disciplined in their Dhamma — assumes form to be the
  self. That assumption is a fabrication. Now what is the cause, what is
  the origination, what is the birth, what is the coming-into-existence
  of that fabrication? To an uninstructed, run-of-the-mill person,
  touched by that which is felt born of contact with ignorance, craving
  arises. That fabrication is born of that.
  
  SN 22.81 


In the teachings in the Pali suttas, 'rebirth' always includes the delusion of 'an agent' or 'a being', as follows:


  I saw — by means of the divine eye, purified &amp; surpassing the human —
  beings passing away &amp; re-appearing, and I discerned how they are
  inferior &amp; superior, beautiful &amp; ugly, fortunate &amp; unfortunate in
  accordance with their kamma: 'These beings — who were endowed with bad
  conduct of body, speech &amp; mind, who reviled noble ones, held wrong
  views and undertook actions under the influence of wrong views — with
  the break-up of the body, after death, have re-appeared in the plane
  of deprivation, the bad destination, the lower realms, in hell. But
  these beings — who were endowed with good conduct of body, speech, &amp;
  mind, who did not revile noble ones, who held right views and
  undertook actions under the influence of right views — with the
  break-up of the body, after death, have re-appeared in the good
  destinations, in the heavenly world.' Thus — by means of the divine
  eye, purified &amp; surpassing the human — I saw beings passing away &amp;
  re-appearing, and I discerned how they are inferior &amp; superior,
  beautiful &amp; ugly, fortunate &amp; unfortunate in accordance with their
  kamma.
  
  MN 4


As long as the mind continues to construct the idea of 'self', 'agent', 'person' or 'being', rebirth will continue. This is samsara. Samsara is circling around in self-views, as follows:


  "Just as a dog, tied by a leash to a post or stake, keeps running
  around and circling around that very post or stake; in the same way,
  an uninstructed, run-of-the-mill person — who has no regard for noble
  ones, is not well-versed or disciplined in their Dhamma; who has no
  regard for people of integrity, is not well-versed or disciplined in
  their Dhamma — assumes form to be the self, or the self as possessing
  form, or form as in the self, or the self as in form.
  
  "He assumes feeling to be the self...
  
  "He assumes perception to be the self...
  
  "He assumes (mental) fabrications to be the self...
  
  "He assumes consciousness to be the self, or the self as possessing
  consciousness, or consciousness as in the self, or the self as in
  consciousness.
  
  "He keeps running around and circling around that very form... that
  very feeling... that very perception... those very fabrications...
  that very consciousness. He is not set loose from form, not set loose
  from feeling... from perception... from fabrications... not set loose
  from consciousness. He is not set loose from birth, aging, &amp; death;
  from sorrows, lamentations, pains, distresses, &amp; despairs. He is not
  set loose, I tell you, from suffering &amp; stress.
  
  SN 22.99


"A being" is merely a view or idea, as explained below:


  Why now do you assume 'a being'? Mara, have you grasped a view? This
  is a heap of sheer constructions: Here no being is found.
  
  Just as, with an assemblage of parts, The word 'chariot' is used, So,
  when the aggregates are present, There's the convention 'a being.'
  
  It's only suffering that comes to be, Suffering that stands and falls
  away. Nothing but suffering comes to be, Nothing but suffering ceases.
  
  SN 5.10