There are 'proofs' that contain errors, just as there are science papers that reach incorrect conclusions. Also, it's not necessarily easier to verify a proof

There are 'proofs' that contain errors, just as there are science papers that reach incorrect conclusions. Also, it's not necessarily easier to verify a proof than it is to repeat an experiment (or perform additional supporting experiments), especially for complex proofs which very few people know enough to completely understand (eg. of Fermat's last theorem, or the Poincare conjecture).