Not even sure why the main thing they’re complaining about is the “dirty tricks”,

The article you posted explains it:

Furious Democrats accused Republicans of playing “dirty pool.” They said Republicans pulled Rep. Mark Takano (D-Calif.), the ranking member of the House Veterans’ Affairs Committee, away from the podium, where he was leading the Democratic side of the debate, in order to discuss changes to the bill. It was during that parley — while Takano was away from his microphone — that McDowell fast-tracked the proposal, they said.

“After publicly announcing a recorded vote on the TCAVA legislation, House Republicans asked if RM Takano and Democrats would agree to last minute engrossment corrections,” a Democratic leadership aide said.

“While members and staff were evaluating these changes away from the podium, House Republicans called the vote up and passed it by voice within seconds — depriving Democrats of the ability to even evaluate the proposed changes and ask for a recorded vote so Members could vote against the biggest cut to veterans benefits in US history,” the aide added.

“On Veterans Day of all days, using dirty tricks to steal from Veterans is a disgrace.”