True flower bulb tissues are fleshy and layered, somewhat like an onion, with a root plate connecting all of the layers of the bulb at the bottom. When crushed, the bulb tissues can compress, be pushed apart and separate, or simply be dented depending on the power and weight of the impact. Most true bulbs can be cut into pieces down the top to bottom axis and still successfully grow and reproduce when planted--so crushing is not necessarily tantamount to destroying a flower bulb.
Disturbed or Ripped Roots
When bulbs planted in soil get trampled or crushed, the soil will absorb much of the shock but the roots will likely be crushed, ripped out of place or even away from the root plate. While this will not destroy the bulb it may slow or halt growth temporarily. The roots will require time to regenerate themselves and knit into the surrounding soil again. It is also possible that the above-ground foliage and flower from the bulb will continue to live off the stored energy in the bulb and the effect of damage will not be readily visible.
Pushed Deeper Than Planting Depth
Bulbs planted in the soil can be pushed further down in the soil than their recommended planting depth which can be problematic if they are displaced more than an inch or two. Some bulbs are very forgiving in their planting depth but others such as amaryllis, which are planted with their shoulders exposed above the soil, will need to be raised back into position in order to grow and bloom properly.