deleting experiment: strange behavior ?

why in some cases I am able to delete an experiment: https://www.beat-eu.org/platform/experiments/smarcel/tutorial/digit/1/character-recognition-mlp-nhu10-iter50/

and not: https://www.beat-eu.org/platform/experiments/smarcel/tpereira/full_isv/1/test3/

in both base experiments are private