、。
Long story short, they stiffed their creditors and bolted.
Literal
In-short, debt [obj-を] stomp-topple-[and-て] ran-off-[regrettably-ちまった].
要するに is a discourse connector wrapping up a preceding argument: 'to sum up / in short.' 踏み倒す literally 'to trample down and topple,' but as a fixed verb it means 'to skip out on paying a debt' — a vivid idiom that captures English 'stiff someone' well. 逃げちまった is the blunt masculine contraction of 逃げてしまった, where しまう carries the 'regretfully / completely / unfortunately' nuance of a completed action with negative shading. The ちゃった/ちまった contraction is strictly casual.